a11y-toolkit: VPAT 2.5 report (WCAG edition)

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

Annotations only declare readOnly=false, destructive=true, idempotent=true, openWorld=false; the description adds substantial context beyond them: levels start at 'Not Evaluated', automated fails force 'Does Not Support', the document is a DRAFT until the signature block (referencing pack sha256) is completed, and a file is written only when output_path is given. This is exactly the behavioral disclosure a mutation tool needs.

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 and information-dense, but redundant: the a11y_generate_declaration counterpart relationship is stated twice, and 'the machine fills Remarks, the human signs the claim' plus the 'levels stay Not Evaluated until a qualified human sets them' point are repeated across the main text and the trailing recap.

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?

For a 12-parameter, nested-object tool with no output schema, the description supplies the return shape ({html, summary, levels, pack_sha256, draft}), the draft/signature workflow, the override semantics, and the file-write condition. An agent has everything needed to invoke it correctly.

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 description coverage is 100%, so the baseline is 3, but the description adds real semantics: it explains the pack-versus-reports relationship, that the pack is built from reports when absent, the accepted override level vocabulary, and the conditional file-writing behavior of output_path. It adds value over the schema without fully re-documenting every field.

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 ('Generates a VPAT 2.5 (WCAG edition) accessibility conformance report in accessible HTML from an a11y_evidence pack'), including the exact artifact (55-criterion WCAG 2.2 A/AA table). It explicitly distinguishes itself from the sibling a11y_generate_declaration by positioning VPAT as the US/ADA counterpart versus the EU/EAA declaration.

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 clear when-to-use context ('Run after the audits you trust'), names the required input source (the a11y_evidence pack, or raw reports), and routes the agent between this tool and a11y_generate_declaration by region/standard. The preconditions (qualified human must set levels and sign) are spelled out.

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