browser_downloads

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

With no annotations, the description carries the burden of behavioral disclosure. It clearly conveys a read-only list operation and discloses the scope ('during this session') and the exact data returned (url, filename, saved path). While it does not mention edge cases like 'no downloads' or 'list reset behavior', the simple nature of the tool makes this acceptable.

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 a single, front-loaded sentence that immediately states the verb and object, then adds the return fields in parentheses. Every word earns its place; there is 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?

This is a low-complexity tool with no parameters and no output schema. The description fully specifies what it does, the session scope, and the composable return fields. There are no gaps in its context for an agent to invoke it 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?

The tool takes zero parameters, so the description does not need to explain parameter meanings. The baseline for 0-parameter tools is 4, and the description appropriately focuses on behavior rather than arguments.

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 uses a specific verb ('List') with a clear resource ('files downloaded during this session') and specifies the return fields (url, filename, saved path). This clearly distinguishes it from all browser siblings, none of which deal with downloads.

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 tool's purpose is self-evident: use it to see files downloaded during the current browser session. There are no alternative tools among the siblings for this function, so explicit when-not-to-use guidance is unnecessary. The context is clear, and no exclusions are missing.

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