describe_image

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

With no annotations, the description carries the full burden. It discloses the default model (gemini-2.5-flash), which is useful, but does not mention that it sends image data to an external API, potential rate limits, or that it performs no modification (read-only behavior). The description is not misleading but lacks depth.

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?

A single, focused sentence that front-loads the purpose and adds the crucial default model detail. No redundant words 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 tool is relatively simple with 3 params (1 required) and no output schema. The description states the return type (text description) and model, which is sufficient for an AI agent to invoke it generally. However, it doesn't mention the optional question/systemInstruction behaviors, but these are self-explanatory from the schema. Given the simplicity, the description is nearly 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?

Schema description coverage is 100%, so baseline is 3. The description adds no extra parameter-specific semantics beyond what the schema already provides. The default model note is not parameter-related, so the tool description does not enhance parameter understanding.

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 the verb (get) and resource (text description of an image), and it implicitly differentiates from siblings generate_image/edit_image by focusing on analysis of an existing image. The addition of the default model further clarifies scope.

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 (use when you need a text description of an image), but no explicit mention of when not to use it or alternatives. The presence of question parameter is not explained, so the description doesn't guide on whether to use this for specific queries or just general description.

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