image_search

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

With no annotations, the description must disclose behavioral traits. It mentions the tool is in beta with access restrictions, and that results are ranked. However, it omits details on rate limits, error handling, or any side effects. The description is adequate but not comprehensive.

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?

The description is a single paragraph that front-loads the beta access note, then explains the core function and key parameters. It is clear and avoids redundancy, though it could be slightly more concise.

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 search tool with 12 parameters and no output schema, the description covers the main features (result fields, design topic, reference image, domain filters). It provides enough context for an agent to decide when to use it, though it does not explain all parameters or the output structure in depth.

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 100%, so the schema defines parameters well. The description adds value by explaining the special behavior of the 'topic' parameter set to 'design' (structured style summary, html_snippet) and the 'image_url' for reference search. This goes beyond the schema descriptions.

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 clearly states it searches the live web for images, lists returned fields (title, source page, dimensions, etc.), and explicitly says 'not for general text web search', distinguishing it from sibling tools like 'search' and 'news_search'.

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?

The description tells when to use it: 'when the user wants to find pictures, photos, diagrams, or visual references'. It also mentions alternative uses (reference image, design topic). However, it does not explicitly name sibling tools or state when not to use it.

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