explain_pdfua_ruleExplain a veraPDF PDF/UA-1 rule by id (clause-test, e.g. 7.1-3, 7.3-1, 7.18.5-1, 7.21.4.1-1): what it checks, the veraPDF error message, whether the automatic fix removes it and how to fix it in the authoring tool.
| Name | Required | Description | Default |
|---|---|---|---|
| rule | Yes | Rule id, e.g. 7.1-3 |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing the shape of the answer, including whether the automatic fix removes the failure and how to remediate in the authoring tool — exactly the facts an agent needs before deciding to call it.
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?
A single sentence, front-loaded with the verb and resource, then a tight colon-list of outputs. Every clause carries information and nothing is repeated from the schema or annotations.
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 one-parameter read-only lookup with no output schema, the description is essentially complete because it enumerates the return content. The only omissions are edge behavior for unknown or malformed rule ids and whether unknown ids error or return a miss.
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 the baseline would be 3, but the description adds the id format convention ('clause-test') and several additional worked examples (7.3-1, 7.18.5-1, 7.21.4.1-1) whereas the schema offers only '7.1-3'. That materially improves the chance of a valid id being supplied.
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+resource ('Explain a veraPDF PDF/UA-1 rule by id') and enumerates exactly what the answer contains (what it checks, the error message, auto-fix coverage, authoring-tool remediation). The 'clause-test' format plus four concrete id examples make it unambiguous versus the sibling check_pdf_accessibility, which evaluates a document rather than explaining a rule.
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?
The content list implies the intended workflow (look up a rule id surfaced by a failing check) but usage is only implied, never stated. It names no explicit trigger, no when-not-to-use, and does not point to check_pdf_accessibility as the alternative for actually running checks.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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