close_browser

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

With no annotations, the description carries the burden of disclosure. It mentions the side effects of closing the browser and releasing all connections, and specifies the availability constraint. This is adequate for a simple no-parameter tool.

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 two concise sentences, front-loading the action and impact, with no redundant information. It earns its place by providing both the primary effect and the important limitation.

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 simple tool with no parameters and no output schema, the description adequately explains what it does and its constraint. It could mention when to prefer this over sibling session-management tools, but the current scope is sufficient.

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 the schema is fully covered by having no properties. The description does not need to add parameter semantics, and the baseline for zero-parameter tools 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 clearly states the verb 'close' and the resource 'Playwright-managed browser', and specifies the exact scope: browsers launched by this MCP. It distinguishes itself by noting the managed nature, which is relevant given siblings like manage_browser_session.

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 phrase 'Only works for browsers launched by this MCP' provides a clear exclusion, guiding the agent not to use it for external browsers. It doesn't explicitly compare to sibling tools like manage_browser_session, but it gives enough context for when it's applicable.

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