download

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

No annotations provided, so description carries full burden. It comprehensively discloses support for binary/text files, enabled ECH/DoH, proxy support, SSRF protection blocking private IPs, and configurable max download size with hard limit. This ensures the agent understands all key behavioral traits.

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 6 sentences with no redundant text. It starts with the core purpose, then provides differentiation, features, and limitations in a logical order. Every sentence adds value.

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 the complexity (9 parameters, no output schema), the description covers purpose, usage, safety (SSRF), size limits, and networking features. It could mention return behavior (e.g., file saved or error), but overall it is complete enough for an agent to use correctly.

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 each parameter. The description adds minimal extra context (e.g., 'adjustable via max_size_mb, hard limit 2 GB') but does not significantly enhance understanding beyond what the schema provides. Baseline 3 is appropriate.

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?

Description clearly states 'Download a file from a URL and save it to disk.' and distinguishes from webfetch for reading web page content. The verb 'download' and resource 'file from URL' are specific 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?

Explicitly mentions alternative tool webfetch for reading web page content as text. Also describes features (ECH, DoH, proxies, SSRF protection, size limits) that inform usage context.

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