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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description still adds real value: a 15-minute link lifetime surfaced via `expires_at` and an explicit do-not-persist instruction. It omits that this is an authenticated call with per-key agent scoping, but the schema covers those error cases.

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?

Three short sentences, front-loaded with the action and then the crucial expiry constraint; nothing is buried. The opening line largely restates the title, which is the only wasted token.

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, the description steps in to characterize the return value (ordered links plus `expires_at`), the volatility of those links, and the no-media edge case. That covers everything an agent needs to call this correctly and act on the result.

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 coverage is 100% and both required UUID parameters are documented in the schema with their 404/403 outcomes, so the description is not obliged to compensate. It adds no extra meaning about agent_id or attachment_id beyond what the schema already states, which is the baseline-3 case.

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 ('Get links to an AI attachment's files') and clarifies that the result is one read-only link per stored file, in order. It never distinguishes itself from the nearby get_attachment / list_attachments / import_attachment_media siblings, so an agent still has to guess which of those to pick.

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?

Offers genuine operational guidance for the result ('download the files within that time, or ask again; don't store the links') and covers the empty case. But it gives no condition for choosing this tool over get_attachment or list_attachments, so selection guidance is only implied.

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