image

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

With no annotations provided, the description carries full burden and does well by disclosing key behavioral traits: it describes the response format (XML with file paths, images saved to disk), mentions that images are saved rather than returned as base64, and includes best practices for effective usage. It doesn't cover rate limits, authentication needs, or error handling, but provides substantial operational context.

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 well-structured with clear sections (CAPABILITIES, RESPONSE FORMAT, BEST PRACTICES) and efficiently conveys information. While slightly longer than minimal, each section adds value and the structure helps with quick scanning. The final 'Supports:' line feels redundant but doesn't significantly detract.

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?

For a complex 9-parameter tool with no annotations and no output schema, the description provides substantial context about capabilities, response format, and best practices. It covers the tool's scope well but doesn't address potential limitations, error cases, or provide examples of the XML response structure that would help the agent understand what to expect.

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 the schema already documents all 9 parameters thoroughly. The description adds some context about reference images for editing and general capabilities, but doesn't provide additional parameter semantics beyond what's in the schema. This meets the baseline expectation when schema coverage is complete.

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 purpose as 'Generate images via OpenRouter-compatible or OpenAI-compatible endpoints' with specific capabilities listed including text-to-image generation, image editing, and multiple aspect ratios/resolutions. It distinguishes from sibling tools (which appear to be text/chat models) by focusing exclusively on image generation and manipulation.

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 for when to use this tool (image generation and editing) and includes 'BEST PRACTICES' section with specific guidance on prompt construction and editing workflows. However, it doesn't explicitly state when NOT to use this tool or name alternatives for similar functionality.

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