Get a Pexels Photo by ID

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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. Description adds behavioral context: how to handle the output (render image_url as Markdown link, credit photographer) and that IDs should not be guessed. 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?

Extremely concise: one sentence for purpose, followed by three clear usage lines. No redundant information. 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 the tool's simplicity (one param, output schema present), the description covers purpose, usage prerequisites, limitations, and output rendering. Completely sufficient for correct invocation.

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 has 0% description coverage for the single parameter. Description compensates by explaining where to obtain photo_id (previous search result or pexels.com URL ending in -<id>), adding semantic context beyond the raw integer type.

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?

Description clearly states 'Fetch one Pexels photo by id' with a specific verb and resource. It distinguishes from sibling tools by warning against use for discovery and directing to pexels_search_photos.

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?

Explicitly states when to use (have a photo id) and when not to use (discovery, guessed ids). Provides alternative tool (pexels_search_photos) and post-usage instructions (render as Markdown link, credit photographer).

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