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

The readOnlyHint annotation already covers the safety profile, so the description's addition of concrete output details (public URLs and quota) is useful. However, it does not mention pagination, ordering, error behavior, or whether the quota is returned as usage/limit. With no output schema, this is a partial but adequate disclosure for a simple zero-parameter list.

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, tight sentence with the action and resource front-loaded. It contains no filler and every phrase adds useful information.

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 zero-parameter, read-only listing tool with a readOnlyHint annotation, the description is nearly complete: it states the purpose, the scope, and the key output elements. It does not describe the exact response shape or pagination, but given the low complexity this is a minor gap rather than a critical omission.

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 tool has zero parameters, so there is no parameter documentation burden. The baseline of 4 applies, and the description appropriately focuses on what the tool returns rather than parameter details.

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 uses a specific verb and resource: it states the tool will 'List images in the Dplooy Media Library' and clarifies the output includes public URLs and the account's image quota. This clearly distinguishes it from sibling tools like upload_media, delete_media, and other list_* operations without requiring schema inspection.

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 clear context for when to use the tool: when an agent needs to retrieve image URLs or check quota from the media library. It does not explicitly name alternatives or exclusions, but the read-only listing intent is obvious and the sibling list implies upload_media and delete_media handle mutations.

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