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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuinely new behavioral facts: only metadata is returned, the payload fields are enumerated, and binary bytes must be fetched out-of-band from the given REST URL. Missing only ordering/pagination or empty-result 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 tightly written sentences: the operation and its returned fields come first, the binary-content exclusion second. Every clause carries information an agent needs; zero filler.

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?

With no output schema, enumerating the returned fields is exactly the right compensation, and the binary-content pointer prevents a common misuse. Only minor gaps remain (result ordering, pagination for stories with many attachments, behavior on an unknown storyId).

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% and the single storyId parameter is already documented with example formats ("ORB-526" or a Stride UUID). The description adds nothing about the parameter beyond what the schema states, so the baseline of 3 applies.

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?

States a specific verb and resource ("List file attachments on a story") plus the exact scope of what is returned (filename, mimeType, size, uploader, createdAt, url). The "metadata only" qualifier cleanly separates it from binary-download and from the upload/delete_attachment siblings without needing to name them.

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?

Gives a clear condition for use (you want attachment metadata for a story) and explicitly redirects the agent elsewhere for binary content via the REST path. It does not explicitly mention the complementary siblings upload_attachment or delete_attachment, so there is no full when-not-to-use routing, but the usage context is unambiguous.

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