browser_tab_close

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

The annotation already declares destructiveHint=true, so the agent knows this is destructive. The description adds no additional behavioral context, such as what happens to the tab, whether it can be undone, or error behavior if the pageId is invalid.

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 a single sentence, 'Close a tab by stable page ID,' which is concise, front-loaded, and contains 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 simple tab-close operation, the description covers the core function and key parameter. However, it omits session prerequisites or behavior on invalid pageId. Given the annotations and a simple schema, it is adequate but not fully comprehensive.

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 description adds 'stable' to describe pageId, giving it a semantic quality not present in the schema (where pageId is just a string with no description). sessionId is already described in the schema, but the description does not elaborate further.

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 description states 'Close a tab by stable page ID.' It uses a specific verb ('Close') and resource ('tab'), and the phrase 'by stable page ID' clarifies the input mechanism, distinguishing it from sibling tab operations like browser_tab_new or browser_tab_select.

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 explicit guidance on when to use this tool versus alternatives. The description only states the action, with no mention of prerequisites (e.g., obtaining the stable page ID via browser_tab_list) or exclusions for other tools.

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