download_file

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

With no annotations provided, the description carries the full behavioral disclosure burden and succeeds. It reveals session/cookie usage, default waiting behavior, file move semantics, no-replacement unless overwrite=true, timeout fallback behavior, and session_id constraints.

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 five dense sentences with the core purpose front-loaded. Every sentence adds new behavioral or parameter information, with 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?

Given seven parameters, no annotations, and no per-parameter schema descriptions, the description covers most invocation-relevant behavior, including timeout edge cases and session requirements. It is slightly incomplete only on filename semantics and what happens when wait=false, but the presence of an output schema reduces the need to document return values.

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 0%, so the description adds meaning for most parameters: directory, overwrite, wait, timeout, session_id, and url. However, filename's role is not explained, leaving a gap in an otherwise strong parameter-semantics pass.

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 states a specific action—'Download an http(s) URL through the real browser's native download manager'—and clearly identifies the expected result: the final absolute local path. It also distinguishes the tool from a plain fetch by emphasizing that the browser profile's cookies and authenticated session are used.

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 says 'Use this for attachments instead of page fetch,' giving a concrete when-to-use rule and naming an alternative. It also communicates an important usage constraint: an explicit session_id must still be live and is never replaced with another profile.

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