browser_close

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

The annotations already declare destructiveHint=true, readOnlyHint=false, and openWorldHint=true, so the safety profile is covered. The description adds a valuable non-obvious behavioral detail: the persistent profile is not destroyed, which meaningfully clarifies the scope of the destructive action. It still does not say what live session state or tabs are lost when the browser closes.

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 with no wasted words. The essential action is stated first, and the important caveat about the persistent profile is appropriately appended.

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 close operation with no output schema, the description plus annotations provide sufficient context to invoke the tool correctly. Minor omissions remain, such as behavior when no browser is open or confirmation of what session state is discarded.

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?

There are zero input parameters, so there are no parameter semantics for the description to explain. The schema itself has 100% description coverage, and the baseline for a zero-parameter tool is 4.

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 verb and resource: 'Close the Playwright browser.' The parenthetical narrows the scope by clarifying that the persistent profile remains on disk, which distinguishes this from destructive cleanup that would delete profile state.

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 gives no explicit when-to-use or when-not-to-use guidance. It implies end-of-session cleanup, but it does not name alternatives such as browser_tabs, chrome_close_tab, or other browser lifecycle tools.

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