close_tab

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

No annotations are provided, so the description carries the full burden of disclosing side effects. It only says 'Close a tab' and adds a uniqueness constraint, but doesn't state that closing is irreversible, whether the active tab can be closed, or how browser state changes. This is insufficient for a destructive browser operation.

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?

The description is compact and front-loaded; 'Close a tab' is the first sentence and the Args block is terse. Every line earns its place and no redundant schema information is repeated.

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 simple two-optional-parameter tool with an output schema, the core mechanics are present, but key selection details are missing: whether tab_id and url_pattern are alternatives or cumulative, and what happens if no tab or multiple tabs match. An agent could invoke it correctly in the common case but lacks full error and selection context.

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?

With 0% schema description coverage, the parameter lines add necessary semantics: tab_id is 'Exact tab id' and url_pattern is 'Regex matched against tab URLs' with 'Must identify one tab.' This goes beyond the schema's bare property titles, though it doesn't specify whether the two parameters are mutually exclusive or can be combined.

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?

The opening sentence 'Close a tab' names a specific action and resource, and the action is clearly distinct from sibling tools like open_tab, activate_tab, and list_tabs. It tells an agent exactly what operation this tool performs.

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 gives no explicit when/when-not guidance or alternative routing. It relies on the tool name and the closing verb to imply usage, but it never states, for example, to prefer this over navigating away or activating another tab. This is implied usage rather than explicit guidance.

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