Analyze Image (Gemini)

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

Annotations already declare read-only and non-destructive behavior, lowering the bar for description. The description adds that it uses the Gemini API and accepts either base64 or file path, which is useful but does not disclose potential external API costs, rate limits, or error behaviors. No contradiction with annotations; score reflects minimal but adequate transparency.

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?

Two sentences, front-loaded with purpose and a clear use case. No wasted words; every clause adds value (purpose, use case, input methods). Perfectly concise.

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 simple (5 params, 1 required) with good annotations and full schema coverage. The description adequately covers the essential input options and purpose. It does not mention edge cases or error handling, but given the simplicity and existing structured metadata, it is complete enough.

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 descriptions cover all parameters (100% coverage), setting a baseline of 3. The description adds a note about providing either base64 or file path, which clarifies the mutual exclusivity of image and image_path, but this is a minor addition. It does not significantly enhance understanding beyond the schema.

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 sends an image to the Gemini API for visual reasoning, with specific input methods (base64 or file path). This distinguishes it from sibling screenshot tools, which capture images rather than analyze existing ones, and aligns with the context signal that the calling model may lack an image encoder.

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 clear context on when to use the tool ('when the calling model has no native image encoder') but does not explicitly name alternatives or state when not to use it. This meets the 'clear context, no exclusions' criterion but stops short of the top score.

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