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

The description goes well beyond the annotations: it discloses public vs private bucket readability, that public files yield a permanent URL while private links expire in 15 minutes, that anyone with the link can download until expiry, that the agent bearer token is required, and that signed links survive token rotation/revocation. These are exactly the operational facts an agent needs and none are in the structured fields.

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 content is dense and mostly earns its place, but it is poorly front-loaded (opens with a caveat rather than the action) and contains overlapping warnings about placeholder URLs in two separate sentences. The core action is not stated until the third sentence, which hurts scannability.

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 an output schema exists, return-value explanation is unnecessary, and the description still covers auth requirements, link lifetime, public/private semantics, and path rules. For a two-parameter tool with zero schema description coverage, nothing an agent needs in order to call it correctly is missing.

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?

With schema description coverage at 0%, the description carries the burden and largely does: it explains that paths are relative to the agent namespace (server adds the prefix), forbids leading slashes, backslashes, percent encoding and dot traversal, and explains the public/private bucket distinction. It does not restate the path pattern/max length, but the added meaning is substantial.

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 eventually states a specific action and resource: 'request its download link through POST /api/v1/storage/downloads and use the returned download_url', which matches the title. However, the purpose is buried behind an opening sentence about illustrative path values, and no sibling tool (e.g. get_storage, create_storage_upload) is named for differentiation.

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?

It gives clear situational context ('To retrieve a stored file...') and explicit anti-patterns ('do not append the filename to the website origin', 'use only URLs returned by an actual API call'). What is missing is naming of alternatives such as create_storage_upload or get_storage, so the routing decision rests on inference.

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