Search Pexels Photos

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

Annotations include readOnlyHint=true, and the description reinforces 'Read-only'. It adds valuable behavior beyond annotations: returns pre-sized URLs with specific size options, mentions courtesy credit/license terms, and advises picking the closest fit rather than always using 'original'. This enriches the agent's understanding of response behavior.

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 concise and front-loaded: first sentence states the core purpose, second explains return format and licensing, third gives specific usage guidance on URL selection. Every sentence earns its place, with no fluff or repetition.

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, the description sufficiently explains return values (compact photo objects with pre-sized URLs and credit). It covers key usage guidance and licensing. It does not mention pagination metadata or total result counts, but the schema describes page/per_page, so the agent can infer. This is nearly complete for a search 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%, so the baseline is 3. The description mentions the optional filters (orientation/size/color/locale) but does not add semantic detail beyond the schema's own parameter descriptions. It does not clarify parameter usage beyond grouping them as filters.

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's purpose: 'Search Pexels for photos matching a query' with specific verb and resource. It distinguishes from siblings by emphasizing query-based search vs. curated photos or single photo retrieval, and lists optional filters.

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 establishes clear context: use this tool to search photos by query with optional filters. It does not explicitly mention alternatives or when-not-to-use, but the context is sufficiently clear for an agent to select it for search tasks.

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