download

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

Discloses important behavioral details beyond the minimal annotation title: streaming to disk with no memory buffering, SHA-256 integrity verification, optional resume, and the filename resolution precedence. These are meaningful operational traits an agent needs to reason about side effects.

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 compact sentences, each earning its place: the first states core behavior, the second explains filename resolution, and the third gives the usage boundary. No filler 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?

The combination of schema, annotations, and description covers invocation well: URL is required, optional behaviors are explained, and the use case is clear. However, there is no output schema and the description does not state what the tool returns or what happens to an existing file when resume is false, leaving minor post-invocation uncertainty.

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%, so the schema already documents all parameters. The description adds real value by explaining the filename resolution precedence (explicit param → Content-Disposition → URL tail) and framing resume for interrupted transfers, going beyond the schema's bare parameter definitions.

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: download a file over HTTP(S) to disk, with distinctive features like streaming, SHA-256 hashing, and resume. The final sentence distinguishes it from content-reading tools like fetch by emphasizing the FILE is saved, not read as text.

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?

Explicitly says when to use it: for binaries, archives, datasets, documents, and any case where the agent wants the file saved. It also implies the alternative by contrasting with 'not its text content read,' but it does not name fetch or explicitly state 'use fetch instead,' so it stops short of a full 5.

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