Close Tab

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

Destructive behavior is clearly disclosed: 'Closing cannot be undone and tab ids are not reused.' It also explains the fallback resolution behavior for omitted tab_id, adding value beyond the destructiveHint annotation and making side effects explicit.

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?

Four sentences deliver the action, fallback behavior, safety warning, and alternative tool guidance with no filler. The most important information is front-loaded and every sentence earns its place.

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 single-parameter destructive tool with full schema coverage and relevant annotations, the description covers everything needed to invoke it correctly: what it acts on, what happens without an argument, the irreversible consequence, and when to use the sibling tool instead.

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 schema already fully documents tab_id at 100% coverage, including the omit behavior. The description reinforces this but does not add substantially new parameter-level information beyond the 'unless you are certain' caution. A baseline of 3 is appropriate given the complete schema coverage.

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?

'Close one tab' is a specific verb and resource, and the description distinguishes this from sibling close_own_tabs by pointing to the cleanup use case. It clearly identifies what the tool does and how it differs from alternatives.

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 tells when to pass tab_id ('unless you are certain') and when to prefer close_own_tabs ('To clean up after yourself'). It also explains what happens when tab_id is omitted, covering the main usage decision points.

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