rnw_tabs_close

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

No annotations are provided, so the description carries full behavioral burden. Closing a tab is a mutation, and the description says nothing about whether it is reversible, what happens to the closed tab's state, whether an invalid index errors or is ignored, or how the active tab changes afterward.

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?

Two short sentences, front-loading the action and immediately following with the default-case behavior. Every sentence earns its place with no filler.

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-optional-parameter tool with no output schema, the essentials are covered: what it does, and what happens when no index is given. What is missing is disambiguation from rnw_close and any note on error behavior for an invalid index.

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 100% and the schema already documents 'index' as the optional tab index defaulting to the current tab. The description restates this without adding format, indexing base, or out-of-range behavior, so baseline 3 applies.

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 (close) and resource (browser tab) with the default behavior made explicit, so the agent can tell it apart from rnw_close and rnw_tabs_list by name. However it does not explicitly distinguish itself from the similarly named rnw_close sibling, leaving the tab-vs-session scope to inference.

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?

It hints at usage by describing the no-index default, but gives no when-to-use guidance, no prerequisites, and no contrast with siblings like rnw_close or rnw_tabs_select. The agent must infer the boundary between closing a tab and closing a session.

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