image_generate

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

Annotations already indicate readOnlyHint=false, openWorldHint=true, and idempotentHint=false. The description adds two useful behavioral facts beyond these: 'Can incur provider charges' (cost warning) and 'URL results are returned without downloading' (return format). These are meaningful additions that help the agent anticipate side effects and output handling. No contradictions with annotations. Given the annotation coverage, a 4 is appropriate.

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 three sentences, front-loaded with the core purpose, then adding adapter choice, cost warning, and URL return behavior. Every sentence contributes unique information with no redundancy or filler. This is exemplary conciseness.

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 only two parameters (one required) and no output schema, the description covers the essential points: what it does, how to select an adapter, cost implications, and the fact that results are URLs. It doesn't address error handling, rate limits, or prompt best practices, but for a simple image-generation tool with these annotations and no output schema, it is reasonably complete. A 4 reflects that it's sufficient but not exhaustive.

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 0%, so the description must compensate for parameter meaning. It mentions the 'adapter' parameter with its three enum values, which are already in the schema, and implies the 'prompt' is the text to generate from, but it doesn't elaborate on prompt format or constraints (e.g., style, length). The description adds some value (cost, URL results) but doesn't fully explain the parameters' semantics beyond what the enum and type already show. A baseline of 3 is fair.

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 action ('Generate an image') and the resource (a dynamically discovered image model), with the adapter choice ('auto, chat or images') adding specificity. It does not explicitly name or contrast sibling tools like gemini_flash or gemini_vision, so it doesn't fully distinguish itself, but the notion of a dynamic model with adapter selection implies a flexible generic alternative. Hence a 4 rather than a 5.

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 gives some context on how to choose the adapter ('auto, chat or images'), which is internal to the tool, but offers no guidance on when to use this tool versus its siblings (gemini_flash, gemini_vision). There is no explicit mention of alternatives or exclusions; usage is implied by the 'dynamically discovered' phrasing. This is adequate but not explicit, so a 3.

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