Google Images

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

Annotations already declare readOnlyHint, openWorldHint, and destructiveHint, so the safety profile is covered. The description contributes the per-call credit cost and the shape of returned data, which are genuinely additive. It says nothing about result volume, pagination limits, or what an async job response looks like, which are the remaining behavioral gaps.

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 short sentences, with the core action front-loaded, and no filler. The leading 'Google Images.' merely restates the title and name, which is the one wasted fragment, but the rest is tightly written.

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 ten-parameter, read-only search tool with full schema coverage and annotations covering safety, the description is nearly sufficient: it names the source, the return payload, and the cost. The absence of guidance on when to prefer this over brave_images and on the async workflow are the only meaningful omissions.

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%, so all ten parameters (query, gl, hl, cr, lr, page, safe, fields, google_domain, async) are already documented in the schema. The description adds no parameter-level meaning beyond the credit note tied to the fields parameter. Baseline 3 applies because the schema does the heavy lifting.

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 uses a specific verb and resource ('Search Google Images via API') and enumerates the returned fields (URLs, titles, sources, dimensions), so the agent knows exactly what the tool produces. It does not distinguish itself from close siblings such as brave_images or google_videos, leaving the choice between image search providers to the caller.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no mention of the sibling image-search tools (brave_images) that could substitute. The only contextual note is a pricing statement ('1 credit per call'), which is useful but is not usage guidance.

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