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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered. The description adds that the images are 'authentication reference material' PSA 'keeps on file', which gives useful framing about what the images represent, but discloses nothing about pagination, image counts, or auth requirements beyond the annotations.

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 sentences, front-loaded with the resource definition and content examples, then the parameter provenance. Reasonably tight, though the parenthetical enumeration and 'and more' are slightly padded.

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-value explanation is not required, and only one parameter exists. The description supplies enough content and provenance context for an agent to call it correctly; only sibling differentiation and pagination behavior are 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 description coverage is 100% and the single SubjectID parameter is already documented in the schema. The description's 'subject_id is the numeric id from a psa_autographfacts_subjects result' essentially restates what the schema field description says, adding no new format or constraint detail - the baseline 3 for fully covered schemas.

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 resource and scope: 'One autograph subject's full exemplar image gallery' with enumerated content types (signed photos, cards, baseballs, letters, contracts). An agent can distinguish it from siblings like psa_autographfacts_subject (single subject detail) and psa_autographfacts_subjects (list) without opening any 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 provides a prerequisite - subject_id must come from a psa_autographfacts_subjects result - which usefully chains the calls. However, it never explains when to reach for this gallery versus the subject detail tool, nor any exclusion conditions. Usage is implied rather than prescribed.

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