Search photos

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

With no annotations, the description carries the full burden. It discloses default inline thumbnails and token cost (~75 tokens each), enabling the agent to understand behavioral expectations. However, it omits details on pagination, sorting, and potential rate limits, preventing a perfect 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?

Two concise, front-loaded sentences with no wasted words. The first sentence immediately states the action and resource, and the second provides key behavioral details. Every sentence adds value.

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 9 parameters, no output schema, and no annotations, the description is incomplete. It explains output format and default previews but lacks details on pagination, error handling, or result ordering. More context would be needed for an agent to use it reliably without external knowledge.

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 56%, so the schema partially documents parameters. The description adds context for the 'previews' parameter (default behavior and token cost) and hints at output structure, but does not significantly improve understanding of other parameters like page, locale, or orientation beyond what the schema provides.

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 'Search Pexels photos' and specifies the output format (compact line with id, dimensions, photographer, etc.), making the tool's purpose unambiguous. It naturally distinguishes from siblings like search_videos by mentioning 'photos' and the unique inline thumbnail feature.

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 implies use for searching photos with visual validation, but provides no explicit guidance on when to use this tool versus alternatives like batch_search, preview_photos, or curated_photos. No when-not-to-use or exclusion criteria are given, leaving the agent to infer proper usage.

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