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

Annotations already cover read-only, idempotent, open-world, non-destructive. The description adds real value beyond them: original images stay at the museum (no binary retrieval), warnings and observation times must be preserved downstream, and it explicitly disclaims granting permission or refreshing rights. Return format/pagination is not described.

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?

Four tight sentences, front-loaded with the payload and followed by the operational caveats. No filler, though the final three sentences drift into caveat/warning territory rather than pure instruction.

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 no output schema, the description usefully enumerates the returned fields (metadata, image URL, rights evidence, credit) and the behavioral/legal boundaries. The main gap is the undocumented format and locale parameters, but overall it is complete enough for a read-only retrieval tool.

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 only 33% and the description body says nothing about the parameters. The nested ref object carries its own useful guidance (sourceKey, museumObjectId, normalized.imageId.value, observationId; never invent identifiers), but format and locale enums/defaults are undocumented in both prose and schema, so the description fails to compensate for the coverage gap.

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 verb (Return) and enumerates the concrete payload: museum metadata, original image URL, rights evidence, and credit, scoped to a known Finder reference. This is clearly distinguishable from still_generate_citation or still_search_open_art, though it does not name any sibling explicitly.

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?

"for a known Finder reference" implies a precondition (you must already hold a Finder result) and "does not grant permission or refresh source rights" is an exclusion, but neither names the sibling tools (e.g., resolve/search) that produce that reference. Usage is implied rather than stated.

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