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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds the scoping behavior that only publicly accessible images are searched by default, but says nothing about pagination, result ordering, or rate limits.

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?

A single compact sentence with the searchable fields and default scope front-loaded; no filler or redundancy.

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?

For a read-only 4-param search with no output schema, the description covers what is searched and the default scope, but omits sibling differentiation and pagination via cursor. Adequate but with clear gaps.

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 75%, so most parameters are already documented. The description helpfully clarifies what the required query matches on (title, description, prompt, tags) — information not in the schema — but adds nothing for scope beyond the default already stated, and cursor remains undocumented.

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 (Search) and resource (stored images) and enumerates the fields matched against (title, description, prompt, tags), which is more precise than the title alone. It does not distinguish itself from close siblings like images_list, images_daily, or images_get, so it stops 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?

"Search accessible stored images ... public by default" implies when the tool applies and tells the agent the default scope, which is useful context. However, there is no explicit guidance on when to use this versus images_list or images_get, and no exclusions.

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