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

Beyond the read-only, idempotent and non-destructive annotations, the description discloses result states (passed/failed/unknown), rule evidence, timeout, price, no-free-tier, failure charging, and that the original is never changed. The final untrusted-data warning is partly boilerplate, but overall behavioral disclosure is unusually rich.

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?

The purpose is front-loaded and most facts are useful, but the text is fragmented and contains errors such as 'Returns validates' and an irrelevant warning about 'on-chain strings'. The double period and sentence-fragment style reduce polish.

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 two-parameter validation tool with a full schema and an output schema, the description covers the essential context: supported profiles, input size, timeout, cost, result states, and non-mutation of the original.

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 profile enum and base64 file size limits are already documented in the schema. The description reinforces the PDF/A profiles and 10 MB limit but adds no format or semantic detail beyond the structured fields.

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?

The description states a specific verb and resource: validate an inline PDF against PDF/A profiles 1b, 2b, 2u or 3b using veraPDF. It also explicitly excludes conversion, which helps separate it from PDF conversion tools in the sibling list.

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?

It gives clear usage context: one inline PDF, maximum 10 MB, no conversion, and PDF/A-specific validation. However, it does not name alternatives such as pdf_inspect or check_pdf_accessibility, so the agent must infer when another sibling is more appropriate.

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