Validate PDF/UA structure

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=false. The description adds valuable context that it is a 'fast structural gate', describes the response shape and how to interpret errors and warnings, and clarifies limitations. No contradictions.

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 description is concise, front-loaded with purpose, and every sentence adds value. It is well-structured without unnecessary verbosity.

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?

Given the complexity of PDF/UA validation, the tool has a simple schema (1 param), annotations cover safety, and an output schema exists (referenced in description). The description explains the response shape, how to interpret results, and what the tool does not check, making it complete for an agent to use.

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% and the single parameter pdfBase64 is well-described in the schema. The description adds workflow context (validate after generation) but does not provide additional details about the parameter beyond what the schema already provides. Baseline 3 plus extra context justifies 4.

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 clearly states it is a 'Read-only PDF/UA structural conformance check' and lists specific checks (catalog, StructTreeRoot, etc.). It distinguishes itself from siblings by stating it is not a full reference validator like veraPDF.

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 description explicitly says when to use: after generating accessible input with pdfA='pdfa2u'. It also lists what it does not check (fonts, color, rendering) and mentions an alternative (veraPDF) for full validation.

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