browser_tab_close

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

With no annotations, the description carries the full burden. 'Close' implies an irreversible destructive mutation, but the description never says whether the close is permanent, what happens if both tab_id and index are supplied, how switch_to affects focus, or whether closing the final tab terminates the session. For a destructive tool with zero annotation coverage this is a significant gap.

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 short sentence with no filler and the action front-loaded, which is structurally sound. However, the brevity reflects under-specification rather than disciplined conciseness.

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?

An output schema exists, so return values need not be explained. But for a destructive 4-parameter tool with no annotations and no parameter documentation, the description omits the selection semantics, the switch_to behavior, and the side effects an agent must know before invoking it.

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 description coverage is 0% across 4 parameters. The description names tab_id and index but does not explain that they are alternative selectors, nor does it mention switch_to (default 'last_active') or session_id at all, leaving half the parameters undocumented in both schema and description.

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+resource ('Close a tab') and names the two identifiers it accepts, which lets an agent distinguish it from browser_tab_switch, browser_tab_new, and browser_tab_list. It stops short of stating scope (does it close the active tab? is a session teardown implied?), but the core action is unambiguous.

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?

There is no when-to-use guidance, no note on what happens when closing the active or last remaining tab, and no pointer to sibling tools. The agent must infer everything from the tool name.

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