Close duplicate tabs

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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description adds real value by identifying precisely what is destroyed (only duplicate copies, never the first) and the safety predicate that prevents data loss (unmodified, matching copies). It does not say whether anything is returned (list of closed tabs) or what happens when nothing matches, which keeps it below a 5.

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 sentences, front-loaded with the action and outcome, then the safeguard. Nothing is redundant and no sentence could be removed without losing information.

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 two-parameter tool with full schema coverage and no output schema, the description covers action, retention rule, and safety condition adequately. The remaining gaps are the return value and the parameter-interaction rule, which are minor given the tool's simplicity.

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% and both parameters are documented in the schema, so the baseline is 3. The description's 'keeping the first' hints at selection order, but it adds no meaning about how `name` and `duplicates` combine or what an omitted `name` does.

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 ('Closes extra copies of a tab') plus the exact retention rule ('keeping the first'). No sibling tool deals with tabs, but the description still makes the operation and its outcome unambiguous without opening the schema.

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 defines the guard condition under which a copy is closed (matching name, format, element and texture count, and no edits), which implicitly scopes usage. However, it never states when an agent should reach for this tool, when it should not, or how the two parameters interact (e.g., name plus duplicates=true).

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