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 useful context that the images are real, captioned, authenticated reference material PSA keeps on file, but says nothing about pagination, volume, or response behavior beyond that.

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 and followed by the parameter provenance; every clause is informative. It is slightly dense but not 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 values need not be described, and the description covers what the gallery contains plus where the required id comes from. For a single-param read tool this is close to complete, missing only when-to-prefer guidance.

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 0% and the single SubjectID property has no schema description, so the description carries the burden. It clarifies the parameter is a numeric id sourced from a psa_autographfacts_subjects result, adding real meaning beyond the bare string type.

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 names a specific resource ('One autograph subject's full exemplar image gallery') and enumerates the content it holds (signed photos, cards, baseballs, letters, contracts). An agent can tell this apart from psa_autographfacts_subject/subjects by the gallery framing, though no sibling is named explicitly, keeping it just short of a 5.

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 supplies the key prerequisite, stating SubjectID is the numeric id from a psa_autographfacts_subjects result, which tells the agent how to source the input. However, it gives no explicit when-to-use-vs-alternatives guidance (e.g., gallery vs psa_autographfacts_subject), so usage is only implied.

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