close_page

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

With no annotations, the description must disclose behavioral traits, and it does so by stating 'refuses to close the last browser window.' This is a crucial safety/limitation behavior. However, it doesn't detail what happens if that occurs (e.g., error message) or mention other side effects, but the key behavioral constraint is transparent.

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 compact and front-loaded, stating the core purpose in the first phrase ('Low-level tab close tool'), then providing a key behavioral note, and finally an alternative. Every sentence adds value with no 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?

For a simple tool with one optional parameter and no output schema, the description covers purpose, a critical behavioral limitation, and guidance on alternatives. It does not explicitly explain behavior when no page ID is provided (e.g., default current tab), but the overall context is sufficient for most cases.

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 input schema has 100% coverage for the single parameter 'page' with description 'Optional page/tab ID to close'. The tool description does not add additional parameter semantics, so the baseline of 3 is appropriate since the schema already provides sufficient meaning.

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 tool is a 'low-level tab close tool' with a specific scope: closing tabs. It also distinguishes itself from the sibling tool close_managed_tabs by positioning itself as a low-level compatibility tool, which differentiates its purpose.

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 'Prefer close_managed_tabs for BrowserPilot-managed lifecycle cleanup', providing clear guidance on when to use this tool versus an alternative. It also implies this tool is for direct, unmanaged closing, giving context for appropriate usage.

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