DuckDuckGo image search

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

No annotations present, but description discloses caching (1 hour), pagination metadata, and output structure (image URL, thumbnail URL). Lacks details on rate limits or error handling, which would raise the score.

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?

Three sentences, each adding essential information: purpose, output, filters, and caching behavior. Efficient and well-structured.

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?

Given no output schema, description adequately describes return value (image URL, thumbnail, pagination metadata). Covers input, behavior, and output sufficiently for an agent to use the 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 coverage is 100%, and description adds value by summarizing filter options and explaining pagination usage ('request later pages with page without re-searching'), going beyond 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 the tool searches for images via DuckDuckGo, uses specific verb 'Search' and resource 'images', and is distinct from sibling 'web_search' which handles web results.

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?

Provides guidance on pagination and caching (use 'page' to get subsequent pages without re-searching), but does not explicitly compare with sibling 'web_search' or specify when not to use this tool.

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