browser_close

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses that the action flushes session cookies and storage to disk, which is a meaningful side effect beyond the simple name. It does not mention irreversibility or behavior if called multiple times, but for a simple close operation this is adequate.

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 sentence that front-loads the primary action and then adds a crucial detail (cookie/storage flushing). There is no wasted language, and every word earns its place. It is optimally concise.

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 zero-parameter tool with no output schema, the description is fully sufficient. It explains what the tool does and a key behavioral nuance. There is no missing information that an agent would need to correctly invoke this tool.

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 has zero parameters, so per calibration guidance the baseline is 4. The description adds no parameter-specific details because none exist, and the schema already confirms no inputs. The description appropriately focuses on behavior rather than parameters.

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 precise verb ('close') and resource ('browser'), and adds meaningful nuance ('gracefully', 'flush session cookies/storage to disk'). It clearly distinguishes itself from sibling navigation and interaction tools since no other sibling performs a close operation.

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 implies when to use it—when the user is done with the browser—and there are no competing close tools. However, it does not explicitly state conditions or alternatives, such as 'use browser_open_interactive_window if you need to keep the session' or any when-not-to-use guidance. Given the absence of alternatives, this is acceptable but not explicit.

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