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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real value beyond them by disclosing the shape and purpose of the payload (an enumeration of all subjects in a category, each carrying a numeric subject_id intended as downstream input). It does not discuss pagination or result-size behavior, but the output schema covers the return format.

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?

Two dense sentences with zero filler. The scoping statement comes first, followed by the input-source and downstream-use notes, so the essential facts are front-loaded.

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?

With an output schema present, return values need not be described, and the description still supplies the one non-obvious contract detail: the subject_id is the hand-off key to the profile tool. A brief note on result size or pagination would make it fully complete, but nothing needed to call it correctly 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% and the single parameter already documents 'Category id, from psa-autographfacts-categories'. The description's note that category_id originates from psa_autographfacts_categories largely restates the schema, adding no syntax, format, or constraint detail beyond it. Baseline 3 is correct.

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 ('Every autograph subject PSA AutographFacts lists for one category') and explicitly distinguishes itself from its closest siblings: psa_autographfacts_subject (full profile/price guide) and psa_autographfacts_categories (source of the input id). An agent can route between the three without opening a schema.

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 workflow context: category_id comes from psa_autographfacts_categories, and each returned subject_id is then passed to psa_autographfacts_subject. That is strong chaining guidance, though it never states an explicit exclusion or a condition under which this tool should not be used.

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