get_cover_image

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

No annotations are provided, so the description carries full burden. It only states what the tool does but does not disclose behavioral traits like authentication requirements, rate limits, error handling (e.g., if no cover art exists), or whether the image is cached. The description is minimal on 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?

Two sentences with no fluff: the first states the core purpose, the second explains the 'kind' values. Very concise, but could benefit from a brief note on the 'value' parameter or output format. Still, every sentence earns its place.

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 two parameters and no output schema, the description is incomplete. It explains only one parameter partially ('kind'), and omits details on the required 'value' parameter and the return format (e.g., data URL, base64, binary). No output schema exists. This is inadequate for reliable tool 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?

The description clarifies the 'kind' parameter by listing valid values, which adds value beyond the schema's default-only definition. However, the 'value' parameter (required) is not described at all, leaving its semantics (e.g., entity ID vs name) unclear. Schema coverage is 0%, so the description partially compensates but is incomplete.

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 verb 'Return' and the resource 'entity's cover art as an inline image', and specifies the valid entity kinds. This distinguishes it from sibling get_* tools which return metadata, not images. However, 'inline image' is somewhat ambiguous (e.g., URL vs base64).

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?

No guidance is provided on when to use this tool versus alternatives (e.g., other get_* tools). There is no mention of prerequisites, such as needing a valid entity ID, or when not to use it. The purpose is implied but not explicitly contextualized.

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