list_image_models

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

Explicitly states 'Free, no side effects', which is critical for a tool with no annotations. This clearly informs the agent that the operation is safe and read-only. No further behavioral details are needed for such a simple listing tool.

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 short sentences that front-load the core purpose ('List supported cover image models and their per-call cost') and add a safety note. No wasted words.

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?

Sufficient for a zero-parameter tool with no output schema. Describes the output (list of models and costs) but could be more explicit about the return format (e.g., array of objects). Still, the information is adequate for correct invocation.

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?

No parameters exist (empty input schema). The description correctly adds no parameter info since none are needed. Schema coverage is 100%, and the description is fully adequate.

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?

Explicitly states the tool lists 'supported cover image models and their per-call cost'. The verb 'list' and resource 'cover image models' are specific. Distinguishes from sibling list tools by mentioning 'cover image'.

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?

Implied usage for retrieving available image models and costs, but no explicit guidance on when to choose this over sibling list tools (e.g., list_voices, list_formats). Minimal context for decision-making.

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