get_asset_thumbnail

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

With no annotations, the description reveals the read-only nature and the return format (JSON with 'data' and 'type'). It does not mention potential error scenarios but adequately discloses core behavior beyond what annotations would provide.

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 well-structured: purpose sentence, usage guidance, parameter details, return format. Every sentence adds value with no extraneous text.

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?

The description is complete for this simple tool, covering purpose, when to use, parameters, returns, and behavioral read-only trait. Even with an output schema existing, the description provides necessary context for an agent.

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?

Despite 0% schema description coverage, the description adds full meaning: asset_id is a UUID, size has two options with pixel dimensions and a default. This compensates entirely for the schema's lack of 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 retrieves a base64-encoded thumbnail for a single asset, using a specific verb and resource. It distinguishes itself from siblings by naming alternative tools for batch or album thumbnails.

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 explicitly says when to use ('visually inspect one photo') and when not to (multiple photos: use get_thumbnails_batch or get_album_thumbnails). It also marks the operation as read-only, providing clear context.

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