bcquality/skills/do.md
Jesper Schulz-Wedde b0d71418fa Add AL code generation skill contracts
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: bd6344b4-eafd-4a58-a1c9-5a2d96fa2938
2026-07-14 13:43:31 +02:00

25 KiB

kind id version title
meta-skill do 1 Action Skill — the template every action skill follows

DO

An action skill is a markdown file that tells an agent how to do one concrete job — review a pull request, audit telemetry usage, generate a skeleton — using knowledge files from BCQuality. This document is the template every action skill follows. Orchestrators rely on the template to consume any skill without skill-specific parsing.

This contract is stable. Changes require a PR approved by both maintainers.

What an action skill is

An action skill is a single markdown file with YAML frontmatter. It lives inside a layer:

  • /microsoft/skills/ — platform-endorsed action skills.
  • /community/skills/ — community-contributed action skills.
  • /custom/skills/ — partner or customer action skills (typically in a consumer repo, not in BCQuality itself).

Action skills do not live at the repo root. The files in /skills/ — the three meta-skill contracts (READ, DO, WRITE) and the entry-point skill (entry.md, kind: entry-point) — are the only skills that sit outside a layer. The entry-point skill structurally follows this same four-step pattern but produces a dispatch record rather than a findings-report; see skills/entry.md for its contract.

Frontmatter schema

---
kind: action-skill
id: al-code-review
version: 1
title: AL code review
description: Reviews AL source changes against performance and security guidance.
inputs: [pr-diff, object-list]
outputs: [findings-report]
output-version: 1
bc-version: [26..28]
technologies: [al]
countries: [w1]
application-area: [all]
---

kind, id, version, title, description, inputs, outputs are required and specific to action skills. output-version is optional for backward compatibility and defaults to 1; new output kinds MUST declare it explicitly.

bc-version, technologies, countries, application-area are optional filters that let an orchestrator pre-select applicable skills for a task. They follow the same semantics as in READ.

inputs is a list of abstract input types the skill accepts. Standard values: pr-diff, object-list, file-path, repository, telemetry-query, requirement-spec. Semantics are any-of: the orchestrator supplies whichever listed input types it has, and the skill is invoked with a non-empty subset of its declared inputs. A skill that cannot proceed with the supplied subset MUST return outcome: "not-applicable".

requirement-spec is a path-valued input: its value is only a path to a bounded UTF-8 JSON file conforming to the published requirement contract. It is never inline requirement JSON and is never interpolated into prompt or goal text.

outputs MUST be a single-element list naming the output kind. Defined kinds are:

Entry negotiates the exact kind/version and includes it in every dispatch record. An action skill emits one JSON document of only that negotiated kind.

sub-skills is an optional field. When present and non-empty, the skill is a super-skill that composes other action skills; see Composition below. Values are repo-relative paths to action-skill files.

Required sections

Every action skill MUST contain these five sections, in order:

  • ## Source — declares which folders and tags to search for knowledge.
  • ## Relevance — declares how to filter the candidates.
  • ## Worklist — declares how to narrow filtered candidates to the set that applies to this task.
  • ## Action — declares what the skill does with the narrowed set.
  • ## Output — declares the shape of the produced output; typically a reference to the contract below.

The four-step pattern

Source. List the folders and tag filters to collect candidates from. Sources span layers: an action skill sources from the same domain subfolder across every enabled layer. Example: "Source from /*/knowledge/performance/ and /*/knowledge/security/."

Relevance. Apply frontmatter filters to the candidates. Typical filters: match bc-version against the target environment, match technologies against the languages in scope, match countries and application-area against the consuming codebase's context. The exact matching rules are defined in READ (Frontmatter matching semantics). Files that do not match are discarded.

Worklist. Narrow the relevant candidates to the subset that applies to the current task. This is where the task-specific signal enters: the objects changed in the PR, the queries being audited, the skeleton being generated. Typical moves: match keywords against task vocabulary, match file topics against changed objects, deduplicate by concern.

Action. Execute the skill's work against the worklist. Evaluate each item in the worklist against the task input and emit findings. The action step is where skill behavior differs; the preceding three steps are uniform.

Findings-report output contract

Every action skill with outputs: [findings-report] emits a single JSON document that conforms to this schema:

{
  "skill": { "id": "string", "version": 1 },
  "outcome": "completed | not-applicable | no-knowledge | partial | failed",
  "outcome-reason": "string",
  "summary": {
    "counts": { "blocker": 0, "major": 0, "minor": 0, "info": 0 },
    "coverage": { "worklist-size": 0, "items-evaluated": 0 }
  },
  "findings": [
    {
      "id": "string",
      "severity": "blocker | major | minor | info",
      "message": "string",
      "location": {
        "file": "string",
        "line": 0,
        "range": { "start-line": 0, "end-line": 0 }
      },
      "references": [
        { "path": "string", "sha": "string" }
      ],
      "confidence": "high | medium | low",
      "from-sub-skill": "string",
      "suggested-code": "string",
      "suggested-code-omission-reason": "string"
    }
  ],
  "suppressed": [
    {
      "reference": { "path": "string", "sha": "string" },
      "reason": "layer-precedence | configuration"
    }
  ],
  "sub-results": [
    { "...full nested findings-report..." : null }
  ],
  "skipped-sub-skills": [
    {
      "skill": { "id": "string", "version": 1 },
      "reason": "configuration | not-applicable"
    }
  ]
}

JSON validity

The emitted document MUST be strict, valid JSON per RFC 8259. Inside every string value, all double quotes MUST be escaped as \" and all line breaks as \n; other control characters MUST use their JSON escapes. This is not optional polish — it is the difference between a parseable report and one a consumer silently drops.

AL source is the common failure case. Quoted identifiers (for example Rec."No.") and multi-line snippets routinely appear in message, suggested-code, and suggested-code-omission-reason, and each embedded quote or newline MUST be escaped when placed in a string value. A suggested-code payload that spans several lines is a single JSON string with \n separators, not a literal multi-line block. Emit the document as one JSON value with no trailing commentary, and do not rely on the consumer to repair unescaped output.

Field semantics

outcome (required) —

  • completed — the skill ran end-to-end; findings reflects the full result (including the empty set).
  • not-applicable — the skill's frontmatter filters did not match the task context; the skill declined to run.
  • no-knowledge — the skill ran but found no applicable knowledge files; findings MUST be empty.
  • partial — the skill evaluated part of its worklist but did not finish. summary.coverage reflects the evaluated subset. Set outcome-reason to explain.
  • failed — the skill encountered an error and produced no reliable findings. Set outcome-reason. Consumers SHOULD ignore findings on a failed outcome.

outcome-reason is optional for completed, not-applicable, and no-knowledge; required for partial and failed.

An empty findings array with outcome: completed means the skill ran and found nothing to flag. Orchestrators MUST NOT conflate this with not-applicable or no-knowledge.

findings[].id — a stable identifier for the rule or concern that produced the finding. For citation-based findings (any finding with a non-empty references), id MUST equal references[0].path — the primary knowledge file's repo-relative path. For skills that detect concerns without a direct citation, id is a skill-defined slug (kebab-case, stable across versions of the skill). The same id produced in two runs MUST refer to the same concern; consumers MAY deduplicate findings by id.

When a super-skill rolls up a non-citation finding from a sub-skill (an id that is a slug, not a path), the super-skill MUST prefix the id with <from-sub-skill>: to avoid collisions across sub-skills (for example, a slug missing-test from al-security-review becomes al-security-review:missing-test). Citation-based findings are already globally unique through their repo-relative path and MUST NOT be rewritten.

Agent findings. A skill MAY emit findings that the agent identified through its own reasoning rather than from a BCQuality knowledge file. BCQuality is an additive knowledge layer: it augments the agent's pre-existing review judgement, it does not replace it. An agent finding is encoded by:

  • references: [] — required. An agent finding has no knowledge-file citation by definition; if a citation existed, the finding would be a knowledge-backed finding instead.
  • id — a skill-defined slug, prefixed with agent: (mirroring the <from-sub-skill>: rule). For example, agent:obsolete-find-signature.
  • confidence — capped at medium. Without a knowledge-file citation there is no authoritative basis for high confidence.
  • severity — capped at minor. Agent findings are advisory and non-gating: without a curated rule behind them they MUST NOT carry major or blocker weight, which the severity taxonomy reserves for gating defects. A genuinely severe issue the agent is confident about almost always matches an existing knowledge file (upgrading it to a knowledge-backed finding) or warrants authoring a new one — not a high-severity agent finding. When the underlying impact would otherwise be major or blocker, keep the emitted severity at minor but say so plainly in the message, and flag that the concern should be promoted to a knowledge-backed rule before it can gate.
  • message — non-empty and self-contained. It MUST describe the issue and a concrete recommendation, since a consumer rendering the finding has no knowledge-file footer to fall back on.
  • from-sub-skill — set by super-skills only. The literal string "agent" when the super-skill itself produced the finding from its own cross-cutting reasoning; or the producing leaf's skill.id when the super-skill is rolling up a leaf's agent finding. Absent on findings emitted directly by a leaf (the leaf's own report carries the finding under its skill.id already).

Precision bar — emit agent findings conservatively. Agent findings are the lowest-precision output BCQuality produces: there is no curated rule behind them, so a false positive costs reviewer trust with nothing to point back to. Hold them to a deliberately high bar:

  • Emit only a concrete, demonstrable defect with material impact that a knowledgeable BC reviewer would agree is wrong — not merely different, suboptimal in theory, or not-how-I-would-write-it.
  • Steelman before emitting. State the strongest case that the code is correct as written: a deliberate choice, a valid alternative, or behaviour that depends on code outside the diff. If that case is plausible, do not emit.
  • Never emit as agent findings: stylistic or formatting preferences (outside a dedicated style skill's own domain); speculative or hypothetical concerns — anything you would phrase with "could", "might", or "consider"; issues that depend on code not visible in the diff; valid alternative approaches; or generic software-engineering advice a competent model already applies without prompting (the same exclusion the knowledge-file admission test enforces).
  • When in doubt, omit. Recall is the knowledge files' responsibility; the agent channel exists only for the high-confidence, concrete defect the corpus has not captured yet. A missed low-severity observation is cheaper than a false positive.

Agent findings may be emitted by both leaf sub-skills and super-skills, with different scope boundaries:

  • A leaf sub-skill MAY emit agent findings strictly within its declared domain. al-security-review MAY surface an agent security finding that no knowledge file covers (for example, a case over a security-relevant enum with no else arm), but MUST NOT emit a style or performance agent finding — those are out of scope for the leaf and belong to other leaves or to the super-skill. The leaf's domain is the bounding box.
  • A super-skill MAY emit agent findings of any kind, but its self-review pass is most useful for cross-cutting concerns that span multiple leaf domains (architecture-level smells, error-handling gaps that touch security and reliability, resource lifecycle issues). Domain-specific agent reasoning is the leaves' job; the super-skill should not duplicate it.

Before emitting an agent finding, a skill MUST validate the candidate against the BCQuality knowledge it has already loaded for the task — if a knowledge file matches, the candidate is upgraded to a knowledge-backed finding (and merged or deduplicated against any existing finding that already covers the same concern); if a knowledge file explicitly contradicts the candidate, it is suppressed. For a super-skill rolling up leaf reports, this validation is done against the union of knowledge files all leaves loaded, not just one leaf's set.

Consumers that render output MAY treat agent findings differently from knowledge-backed findings (for example, by labelling them and routing them to a separate review domain). The references: [] marker, together with the agent: id prefix, is the contract they rely on; from-sub-skill: "agent" is the additional marker for super-skill-emitted agent findings.

findings[].severity — see the taxonomy below.

findings[].message — human-readable explanation of the finding. Single short paragraph. No markdown formatting assumptions.

findings[].location — optional. When present:

  • file MUST be a repo-relative path using forward slashes.
  • line is the primary line number, 1-based.
  • range is optional and describes a contiguous line span; start-line and end-line are 1-based and inclusive. start-line MUST equal line when both are present.

Findings without a location are permitted (for example, repository-wide observations).

findings[].references — array of knowledge-file references. Each reference is an object:

  • path (required) — repo-relative path to the knowledge file, forward slashes.
  • sha (optional) — commit SHA the skill read when producing the finding. Consumers SHOULD include sha when the skill was invoked with a specific repo state.

The first reference is the primary reference: the knowledge file the finding most directly cites. Additional references provide supporting context and are not ranked. references MAY be empty only for agent findings (see the findings[].id section above for the full encoding); any other finding MUST have at least one reference.

findings[].confidence — the skill's confidence that the finding is a true positive, given the evidence it evaluated. Not applicability confidence, not severity confidence. Values: high, medium, low.

findings[].from-sub-skill — optional. Set only by super-skills. The skill.id of the sub-skill that produced the finding, or the literal string "agent" for an agent finding the super-skill produced from its own cross-cutting reasoning. Absent on findings emitted directly by a leaf skill — including agent findings the leaf emits within its own domain, which appear in the leaf's own report without this field.

findings[].suggested-code — optional in the schema but expected for mechanical findings. It is a concrete code-replacement payload for the lines indicated by location. When present, the string MUST be a literal replacement for the source lines covered by location.line (or location.range if set) — i.e., what the file would contain after the fix, with no surrounding diff markers, fences, or commentary. Consumers MAY render it as a one-click suggestion in the delivery surface (for example, a GitHub ```suggestion block).

Emit suggested-code whenever the fix is small, local, and mechanical: deleting unreachable code; replacing one expression (Count() > 0not IsEmpty()); moving a local Label to object scope; adding a missing property such as ToolTip, OptionCaption, or DataClassification; replacing a string-concatenated Error with a Label-backed call; changing a permission token; or adding a missing else/guard branch whose replacement is unambiguous from the surrounding diff. When a .good.al companion exists and the diff context matches the .bad.al shape, prefer adapting the .good.al replacement into suggested-code.

Omit suggested-code only when the appropriate fix depends on context the skill cannot determine, when multiple defensible replacements exist, or when the fix spans non-contiguous code. If a finding is mechanical-looking but suggested-code is omitted, set findings[].suggested-code-omission-reason to a short explanation (for example, requires choosing a real event id or fix spans multiple non-contiguous locations). The suggested-code payload supplements message; it does not replace the explanation in message.

findings[].suggested-code-omission-reason — optional. Required when a finding is mechanical-looking but suggested-code is omitted. Short, human-readable reason explaining why no safe one-click replacement was emitted. Consumers MAY use this for telemetry or diagnostics; they do not have to render it in review comments.

suppressed — MUST list every knowledge file that was discarded due to layer precedence or consumer configuration, whenever that file would otherwise have contributed to the worklist. Each entry contains:

  • reference — the suppressed file (same object shape as findings[].references).
  • reasonlayer-precedence when another layer won under READ's precedence rules; configuration when the consumer disabled the file's layer.

sub-results — super-skills only. Array of complete findings-reports, one per sub-skill that was invoked (i.e., every sub-skill not listed in skipped-sub-skills). Each entry MUST itself conform to this output contract. Leaf skills MUST NOT emit sub-results.

skipped-sub-skills — super-skills only. Array of sub-skills that were declared in frontmatter but not invoked. reason is configuration when the orchestrator disabled the sub-skill, or not-applicable when the super-skill's Relevance step ruled it out.

Severity taxonomy:

  • blocker — violates platform-level guarantees; the work cannot proceed as-is.
  • major — significant defect; should be fixed before merge.
  • minor — quality concern; worth flagging but not a gate.
  • info — observation or context; not actionable on its own.

Composition (super-skills)

A super-skill is an action skill whose frontmatter declares a non-empty sub-skills: [...]. A super-skill does not evaluate knowledge files directly; it invokes other action skills and composes their output.

Composition is flat: a super-skill MAY list only leaf skills (skills without their own sub-skills). Nested super-skills are not permitted in v1.

Generation skills are leaves. They MUST NOT declare sub-skills or compose other generation skills.

Section interpretation for super-skills

The five required sections still apply. Their meaning shifts from knowledge files to sub-skills:

  • ## Source — names the sub-skills invoked (mirrors sub-skills in frontmatter).
  • ## Relevance — rules for deciding which sub-skills apply to the current task. A sub-skill is relevant when its declared inputs are satisfied by the orchestrator's provided inputs and the orchestrator has not disabled it via configuration. The super-skill MUST NOT filter sub-skills by task content (for example, by inspecting the diff or the file). Task-level applicability is the sub-skill's own responsibility; sub-skills signal non-applicability by returning outcome: "not-applicable" or outcome: "no-knowledge".
  • ## Worklist — the final list of sub-skills to invoke; the rest go to skipped-sub-skills.
  • ## Action — invoke each worklisted sub-skill with the appropriate subset of inputs, collect its findings-report verbatim into sub-results, and copy its findings[] into the super-skill's top-level findings[] with from-sub-skill set. Findings from a sub-skill with outcome: "failed" MUST NOT be copied into the super-skill's top-level findings[] and MUST NOT contribute to the super-skill's summary.counts (their report is still preserved in sub-results for traceability, consistent with DO's rule that consumers ignore a failed skill's findings).
  • ## Output — the super-skill's output contract, including sub-results and, if any, skipped-sub-skills.

Outcome rollup

A super-skill's outcome is derived from its sub-skills' outcomes. Let S be the multiset of sub-skill outcomes for sub-skills in the worklist (skipped sub-skills do not contribute):

  • failed — every element of S is failed.
  • partial — S contains at least one partial, OR S contains at least one failed alongside at least one non-failed outcome.
  • not-applicable — every element of S is not-applicable.
  • no-knowledge — every element of S is no-knowledge or not-applicable, and at least one is no-knowledge.
  • completed — otherwise (every element of S is completed, no-knowledge, or not-applicable, with at least one completed).

When the worklist is empty (every sub-skill was skipped), outcome is not-applicable; outcome-reason SHOULD describe the skip reasons, for example "all sub-skills disabled by configuration" or "no sub-skill accepted the supplied inputs".

outcome-reason is required for partial and failed and SHOULD summarize per-sub-skill state.

Rolled-up summary

summary.counts is the sum of sub-skill counts. summary.coverage.worklist-size and items-evaluated are the sums across invoked sub-skills.

Suppression scope

A super-skill's top-level suppressed[] remains knowledge-file-only and is typically empty. Knowledge-file suppression is reported by the leaf sub-skill inside its own entry in sub-results. Sub-skills the super-skill chose not to invoke belong in skipped-sub-skills, never in suppressed.

Worked example

A minimal action skill that cites applicable guidance for a changed AL file, without generating findings of its own:

---
kind: action-skill
id: cite-applicable-guidance
version: 1
title: Cite applicable guidance
description: Lists knowledge files relevant to a changed AL file.
inputs: [file-path]
outputs: [findings-report]
technologies: [al]
---
## Source
All files under `/*/knowledge/` across enabled layers.

## Relevance
Filter by `technologies: [al]` and `bc-version` matching the target environment.

## Worklist
Intersect `keywords` with tokens derived from the target file's object name and changed members.

## Action
For each worklist entry, emit one finding with severity `info`, a message naming the concern, and a reference object pointing to the knowledge file.

## Output
Conforms to the DO output contract.

Generated-files-report output contract

The generated-files-report v1 contract is published as JSON Schema at schemas/generated-files-report-v1.schema.json. Its path-valued input contract is schemas/requirement-spec-v1.schema.json. The stable generation action skill is microsoft/skills/generate/al-code-generation.md.

Unlike a findings report, a generated-files report has no findings field. It carries create-only UTF-8 AL artifacts, detailed retrieval coverage, immutable revision-scoped guidance references, omissions, and suppression. Consumers MUST validate the complete JSON document atomically and fail closed before materialization, then independently enforce filesystem symlink, destination non-existence, byte-size, and normalized ID-range policy.

How orchestrators consume output

An orchestrator invokes an action skill with an input appropriate to the skill's declared inputs, receives the negotiated JSON output kind/version, and validates that published contract without inferring shape from the skill ID. Findings reports map to review delivery surfaces. Generated-files reports are create-only proposals and require consumer-owned validation and staging before any workspace change. Skills that need richer semantics MUST evolve a versioned shared output contract rather than add unversioned skill-specific fields.