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

Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint), yet the description adds genuinely non-obvious context: no legal clearance is asserted, museum text must be treated as untrusted data, output groups/warnings/evidence must be preserved, and the search 'may record source observations in the existing evidence journal'. That journaling note sits in mild tension with readOnlyHint=true, but it describes an internal evidence log rather than mutation of user data, so it is disclosed context rather than a direct contradiction.

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?

Purpose is front-loaded in the first clause and the remaining sentences are short, high-density caveats without filler. Some fragments are cryptic ('primary, secondary and aside groups') and assume prior knowledge of the output shape, which costs a little clarity but not much length.

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 11 parameters, no output schema, and zero schema descriptions, the definition compensates well on the safety/output side (warnings, evidence, timestamps, untrusted-data handling, pagination contract) but leaves most filter parameters undocumented anywhere in the tool definition. An agent can call it, but cannot reason about several filter semantics.

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 0% across 11 parameters, so the description must carry the burden and it only partially does. It gives real semantics for one parameter (after must be JSON.stringify(next) passed unchanged) and hints at filters via 'title/artist/period/institution' style naming, but yearFrom/yearTo, minWidth/minHeight, orientation, and q are left entirely to their names.

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 and resource ('Search Open Art Finder for source-declared CC0 / Public Domain Mark images'), so an agent knows this is a discovery/search tool rather than a fetch tool like still_get_open_artwork. It scopes the corpus by license status, which is a meaningful qualifier. It does not, however, name or contrast itself with any sibling tool, so differentiation must be inferred.

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?

Usage context is implied by the license scoping ('source-declared CC0 / Public Domain Mark') and there is one concrete operational instruction ('For pagination pass JSON.stringify(next) unchanged as after'). There is no explicit when-to-use vs. when-to-use-an-alternative guidance, and no statement of when this search is inappropriate compared with still_resolve_artwork or still_get_open_artwork.

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