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 substantive behavioral context: the page contents and, notably, what is absent (no price guide), which prevents an agent from expecting pricing data. Return format/pagination is left to the output schema.

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?

Three tight sentences with zero filler. Content summary comes first, the sibling contrast second, and the parameter provenance last — a sensible front-loaded order.

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. The description covers what the resource is, how it differs from its nearest sibling, and how to obtain the single required id, which is everything needed to call 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 coverage is 100% and the schema already documents SubjectID as the numeric id from a psa-probatfacts-subjects result. The description repeats that provenance rather than adding new semantics, so the baseline 3 applies.

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 resource ('One player's full public reference page') and enumerates its contents (bat-authentication notes, professional models used, signature placement, biography). It explicitly distinguishes itself from psa_autographfacts_subject, so an agent can route between the two without opening either 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?

Names the sibling alternative (psa_autographfacts_subject) and the differentiator (no price guide), and tells the agent where subject_id comes from (psa_probatfacts_subjects). There is no explicit when-not-to-use, but the routing context is clear.

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