gemini_list_models

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

The readOnlyHint annotation already indicates no side effects. The description adds context that the tool lists models specific to the API key and includes the default model, but does not disclose additional behavioral traits beyond what annotations already provide. It confirms safe behavior.

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 a single, concise sentence that fully conveys the tool's purpose without extra words. It is appropriately sized and front-loaded.

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 tool's simplicity (no parameters, no output schema, no nested objects), the description is sufficiently complete. It explains what is returned (models list and default model). However, it does not detail the structure of each model entry, which is acceptable for a list operation.

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 input schema has no parameters, so baseline is 4. The description adds meaning by specifying the model family (Nano Banana / Nano Banana Pro) and that the default model is included, which helps the agent understand what will be returned.

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 lists Gemini image-generation models available to the API key, including a specific model family (Nano Banana / Nano Banana Pro) and the current default model. This provides specific verb and resource, distinguishing it from sibling tools like gemini_image_generate or gemini_list_files.

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 implies usage for checking available models and the default, but does not explicitly state when to use it versus alternatives, nor does it provide exclusions or when-not-to-use guidance. Since it's a simple listing tool, it's adequate but could be improved.

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