browser_close_tab

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

Discloses that only session-owned tabs can be closed, but does not mention error handling, return behavior, or side effects. No annotations to contradict.

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?

Extremely concise with two sentences, front-loaded, no redundant information.

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?

Adequately complete for a simple one-param mutation tool. Minor gap: does not describe behavior when tab not found or already closed.

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?

Schema provides full coverage (100%) for the single parameter with a description. The tool description adds a constraint but no new semantic detail beyond what schema offers.

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?

Clearly states the action (close), resource (browser tab), and method (by ID). Distinguishes from siblings like browser_switch_tab and browser_list_tabs.

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?

Implies use by requiring tab_id from list_tabs and adds a constraint (only session-owned tabs), but no explicit when-to-use or alternatives mentioned.

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