describe_image

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

No annotations are provided, so the description carries the burden. It discloses the local vision model usage and return JSON structure (text, mode, media), which adds useful context. However, it does not mention any side effects, limitations, failure modes, or permission requirements. As a read-only description tool, the risk is low, but behavioral details are minimal.

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: the first conveys the core purpose, the second gives the output format. It is concise, front-loaded, and every word earns its place with no fluff or repetition.

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 absence of annotations and output schema, the description still provides a clear purpose, output format, and parameter context via the schema. It is reasonably complete for a simple, read-only image description tool, but lacks usage guidance and edge-case information, so it is not fully complete.

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?

The schema has 100% parameter coverage with clear descriptions (images, prompt, crop, size). The tool description adds no additional parameter semantics beyond stating the return JSON. Since the schema already documents each parameter thoroughly, the description is not required to compensate, hence a baseline score of 3.

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 function: 'Describe or understand one or more images with a local vision model' and enumerates content types (scene, objects, colors, UI). This is a specific verb+resource pairing that distinguishes it from siblings like transcribe or analyze_video, which target audio/video.

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 provides no explicit guidance on when to use this tool versus alternatives. It never mentions the sibling tools or conditions like 'use for still images; use analyze_video for video'. Usage is only implied by the tool name and image-focused phrasing, which is insufficient for clear tool selection.

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