a11y-toolkit: WCAG 3 draft preview (no score)

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/non-destructive, and the description goes well beyond them: it discloses the pinned draft date, that the mapping is curated not W3C-official, that no score/tier/conformance is produced because thresholds are TBD, and that output is JSON with a fixed key set. That is exactly the behavioral context an agent needs before quoting results to a team.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose, then the disclaimer, then the return shape and cadence — good ordering. The no-score point is made three times ('Informative only', 'NO score, tier or conformance claim', 'never a score'), which is defensible emphasis for a headline risk but is mild redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is no output schema, and the description compensates by enumerating the full return object including outcomes, counts, unmapped and the disclaimer fields. Combined with the draft pinning and non-conformance caveats, nothing an agent needs to call or interpret this tool is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so both parameters are already documented, and the description correctly scopes the input as an audit report whose findings are WCAG 2.2. It adds the source tools the report can come from, but says nothing about the lang parameter or edge cases like what happens to unmapped criteria beyond the 'unmapped' key.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource: it takes an audit report and re-groups WCAG 2.2 findings under WCAG 3 Working Draft outcomes. The framing ('the view layer nobody ships') and the explicit negation of scoring clearly separate it from the audit siblings like a11y_audit_url and a11y_ledger.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives an explicit trigger ('Run after any audit when the team asks "what about WCAG 3?"'), an explicit counter-instruction ('keep auditing against WCAG 2.2'), and a maintenance cadence ('re-baseline on each W3C draft publication, roughly March/September'). An agent knows both when to reach for it and when not to.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.