download

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

With no annotations provided, the description carries the behavioral burden. It discloses that downloads happen automatically, that the tool waits for downloads (status) or returns immediately (list), and that it does not trigger downloads—preventing a common misuse. It does not describe the return format or side effects, but for a simple read-only check tool, the essential behaviors are covered.

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 description is concise and front-loaded with the core purpose. It uses a clean structure: a first sentence stating the function, a key clarification about not triggering downloads, and bulleted usage examples. While it could be slightly tighter (the second sentence could be merged), it is well-organized and each sentence contributes meaning.

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 tool with 3 optional parameters, no required params, no output schema, and no annotations, the description provides sufficient context. It covers the main use cases, explicitly mentions the session scope, explains the waiting behavior, and distinguishes between status and list actions. Nothing an agent needs to call it correctly is missing; the only minor gap is lack of a description of the return value format.

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 input schema already describes all three parameters with 100% coverage, so the baseline is 3. The description adds value by demonstrating usage patterns: the default download() call and the download({ action: "list" }) call, and by clarifying the behavior of the 'action' parameter beyond the enum values (e.g., list never waits). This goes slightly beyond the schema's descriptions.

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 opens with a precise statement: 'Check status of file downloads or list all downloaded files in this session.' This identifies a specific verb (check/list) and resource (downloads) and immediately clarifies the scope. It also distinguishes itself by stating it does NOT trigger downloads, which sets it apart from any potential sibling that might initiate downloads. This is clear and unambiguous.

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 explicitly tells the agent when NOT to use it ('you do NOT need to call this tool to trigger downloads') and when to use it: waiting for a large download or listing downloaded files. It provides concrete call patterns (download() and download({ action: "list" })) and even hints at polling use with 'list' returning immediately. This fully equips the agent to decide when to invoke it.

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