save_file

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

No annotations are provided, so the description carries the full burden. It discloses security behavior (path traversal blocked) and general operation (HTTP GET, any file type). However, it lacks details on error handling (e.g., failed downloads), overwrite behavior, or authentication requirements.

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 with three sentences, front-loading the core action and return value. Every sentence provides essential information, with no redundancy or fluff.

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 tool's simplicity and the lack of an output schema, the description covers key aspects: input parameters, return value, and security. It does not mention sibling tools, but the context is sufficiently clear for an agent to use the tool 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 coverage is 100%, so the baseline is 3. The description adds extra meaning: for 'filename', it explains derivation from URL; for 'output_dir', it clarifies relative/absolute paths and defaults; for 'subdir', it notes auto-creation; and for 'url', it stresses the need for a protocol and fully qualified URL.

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 tool's function: downloading a resource from a URL and saving it locally. It specifies the HTTP method (GET), file type handling, and return value (absolute path). This distinguishes it from sibling tools like 'read_content' or 'screenshot', which do not persist files.

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 provides clear usage context: 'Use to persist crawl artifacts.' It implies when to use the tool. However, it does not explicitly state when not to use it or compare with alternatives, so a slight deduction applies.

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