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

Annotations are all false, so the description must carry the behavioral burden. It discloses that the call is project-scoped, returns the project identity, downloads a single result, and returns a storage_key. It also notes the license handling. It does not state idempotency or side effects, but for a fetch/download operation the provided details are reasonably transparent.

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 sentences, front-loaded with the project-scoping note. Each clause adds value: scope, operation, return value, and license instruction. No filler words or redundancy.

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 must explain the return value, which it does (storage_key for add_sfx, plus project identity). It covers the core workflow and the license obligation. It does not describe error cases or confirmation of download, but for a simple fetch the essentials are present.

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 50%: project_id has a descriptive note, id has none. The description clarifies that 'id' is the search_sfx result id (by its id), adding some meaning. It does not elaborate on id's format or provenance, so the description partially compensates but leaves room for more detail.

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 verb 'Download' and the resource: a search_sfx result identified by its id, scoped to a project. It also mentions the return value (storage_key for add_sfx), distinguishing it from search_sfx (searching) and add_sfx (adding), and is explicit about the project-scoping.

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 implies when to use it: after search_sfx has returned results, to fetch one into the project for later addition via add_sfx. It also gives a specific guideline about repeating the license line when there is an obligation. However, it does not explicitly state when not to use it or name alternatives beyond the implicit add_sfx dependency.

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