image_describe

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

Annotations already declare readOnly, non-destructive, and closed-world, so the safety bar is low. The description still adds genuine value beyond them by stating the return type ('Returns text') and a reliability caveat ('descriptions may be inaccurate') that no annotation conveys.

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?

Three short sentences, front-loaded with the action, then return behavior, then the path constraint. No sentence is filler and nothing is redundant.

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 2-parameter, no-output-schema tool, the description covers action, return type, accuracy caveat, and path format. It omits supported image formats and any notion of latency/cost, but nothing essential for correct invocation is missing.

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 0%, so the description must compensate for both parameters. It does provide meaningful guidance for 'path' ('Use an absolute path'), but 'prompt' is only implicitly characterized as a question, with no length, format, or content guidance.

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?

States a specific verb+resource: asking a vision model a question about a local image file. It is clear what the tool does, but it never names or contrasts with the sibling tools image_ocr or image_decide, so an agent must infer the distinction.

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?

Usage is implied by 'Ask ... a question about a local image file', and there is one concrete constraint ('Use an absolute path'). There is no explicit when-to-use / when-not guidance and no routing to image_ocr or image_decide.

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