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

Annotations already supply the safety profile (readOnlyHint, idempotentHint, non-destructive), so the description only needs to add context. It adds ordering behavior (newest first), scope (all uploaded media in workspaces), and the intended use of IDs. It doesn't discuss pagination, limits, or filtering, but the output schema likely covers return structure.

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 efficient sentences: the first states the core behavior and ordering, the second gives a practical usage note. No redundancy, no filler, and the most important information is front-loaded.

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 parameterless list tool with annotations and an output schema, the description covers the essential context: workspace scope, ordering, and intended use. It could be slightly more explicit about whether all workspaces or only accessible ones are included, but it is not incomplete enough to mislead an agent.

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 the baseline is 4. The schema is empty and the description appropriately adds no parameter-specific detail; there is nothing for an agent to misinterpret.

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 operation: listing every file uploaded in the user's workspaces, ordered newest first. It also specifies a concrete downstream use (attaching media to a post), which helps distinguish it from mutating siblings like media_upload, media_delete, and media_update.

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: use this tool to get media IDs for attaching to a post. It doesn't explicitly name alternatives or exclusion conditions, but the purpose is unambiguous enough for an agent to know when to invoke this list operation versus upload/delete/update siblings.

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