browser_close_tab

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

With no annotations, the description carries the full behavioral burden. It usefully discloses the default-target behavior, but for an inherently destructive operation it does not say the close is irreversible, whether unsaved state is lost, or what happens to dependent tabs.

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?

A single front-loaded sentence with zero wasted words that covers both the explicit and default modes of invocation.

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 one-parameter, no-output-schema tool this is nearly complete: purpose and both invocation paths are covered. The only omission is the destructive/irreversible nature of closing a tab, which annotations do not supply either.

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 coverage is 100%, so the baseline is 3, and the description genuinely adds meaning beyond the schema's terse 'Target ID to close (optional)' by explaining that omitting the ID closes the current tab. It does not specify ID format or how to obtain one, which is a minor gap.

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?

States a specific verb and resource ('Close a browser tab') and additionally defines the default behavior when the optional ID is omitted. This distinguishes it from bulk siblings like browser_cleanup_tabs and from opening tools like browser_new_tab, though it does not name any sibling explicitly.

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 tells the agent the operative condition: pass target_id to close a specific tab, omit it to close the current tab. That is implied usage guidance, but there is no mention of when to prefer this over siblings like browser_cleanup_tabs or any prerequisite such as the tab being active.

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