describe_image

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

No annotations are provided, so the description carries full burden. It mentions reading a local file and using a vision model, but doesn't disclose potential limitations like supported formats, file size, or side effects. The transparency is adequate but not thorough.

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 totaling ~30 words, with the usage advice front-loaded. Every sentence adds value, and there is no redundancy or filler.

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 lacks an output schema and does not specify the format or type of description returned. It also omits constraints like file format or access permissions. For a simple tool, it is slightly incomplete but not critically lacking.

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%, with both parameters described in the input schema. The description adds no additional parameter-level details beyond what the schema provides. Since baseline is 3 for high coverage, this score 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 'Reads a local image file and describes its content', specifying the action and resource. It also includes a usage hint distinguishing it from direct reading, and the sibling tools are all generation tasks, making differentiation clear.

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 'Use this when you cannot directly read a local image', providing a clear when-to-use condition. It doesn't list when not to use or alternatives, but the context and sibling tools imply it's for image description when direct access isn't available.

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