download

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

With only a title annotation, the description carries the behavioral disclosure burden. It does well by revealing no-memory-buffering streaming, SHA-256 hashing, resume behavior, and the filename resolution precedence. It falls short of 5 because it does not disclose the return value, where the file lands on disk, or how failures are surfaced.

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 tight sentences with no filler. The core behavioral constraint is front-loaded, filename resolution is compressed into a clear chain, and the usage guidance closes the description efficiently. Every sentence earns its place.

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 download tool, the description is largely complete: purpose, major behavioral traits, filename handling, and use cases are all present. However, without an output schema or supporting annotations, the absence of return-value details, target path, and failure-mode expectations leaves a moderate gap for an agent that must verify the tool's 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 description coverage is 100%, so the baseline is 3; each parameter is already described in the schema. The description adds meaningful context for 'filename' via the resolution precedence chain (explicit → Content-Disposition → URL tail), but it does not deepen semantics for url, resume, cookies, or use_proxy beyond what the schema provides.

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 specific verb and resource ('Download a file over HTTP(S)') and immediately adds distinguishing mechanics: streaming to disk, SHA-256 integrity hash, resume, and filename resolution. It also explicitly contrasts with reading text content, which differentiates it from sibling tools like fetch.

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 final sentence gives a clear when-to-use rule: binaries, archives, datasets, and documents where the agent wants the FILE saved. It also states the when-not condition ('not its text content read'), effectively routing the agent toward a fetch-style alternative for text retrieval.

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