Curated Pexels Photos

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

Annotations already declare readOnlyHint=true, so the description's 'Read-only' is redundant but reinforces safety. However, it adds valuable behavioral context: the hourly refresh, pagination, and the URL structure guidance ('pick the closest fit rather than always using original'). No contradictions.

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 two sentences with zero fluff. The first sentence states the core function, and the second sentence provides a concise, actionable detail about URL sizes. Every word earns its place.

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 simple list tool with no output schema, the description covers return values ('compact photo objects'), pagination, refresh rate, and provides useful details about the `src` object. It lacks only minor aspects like error handling or rate limits, but these are not critical for such a straightforward 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 description coverage is 100%, with both parameters (page, per_page) clearly described. The description adds no new parameter-specific semantics beyond mentioning pagination, which is already implied by the schema and parameter names. Baseline 3 is appropriate.

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 with a specific verb ('List'), resource ('Pexels' hand-curated photo picks'), and adds distinctive details ('refreshed hourly', 'paginated'). This differentiates it from sibling tools like pexels_search_photos and pexels_get_photo by emphasizing the 'curated' nature.

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 gives clear context for when to use the tool (when you want curated content, not search results), though it doesn't explicitly name alternatives or exclusions. The note about picking the closest URL size is a practical usage guideline for the output.

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