close_tab

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

The annotations already declare this as destructive (destructiveHint=true) and not read-only, so the baseline safety profile is known. The description adds valuable behavioral context by explaining that closing the active tab triggers an auto-switch to the next available tab and that the browser context is released. This goes beyond the annotations and gives a clearer picture of consequences.

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 extremely concise and well-structured. It opens with the main action, adds one key behavioral note, and then lists the parameter. Every sentence earns its place, with no redundant or verbose content.

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 tool with a single parameter and an output schema, the description covers the essential behavior and a critical edge case (auto-switch on active tab). It does not explain error cases or prerequisites, but these are less critical given the simplicity and the presence of annotations and an output schema. It is nearly complete for its complexity level.

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 0%, so the description must compensate. The Args section says 'name: Tab identifier to close,' which adds a minimal semantic label but does not explain how to obtain the identifier, what format it should be in, or how it relates to other tools like list_tabs. This is barely more informative than the schema's generic 'Name' title.

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 starts with a clear verb+resource construction ('Close a tab') and adds a meaningful behavioral detail ('release its browser context'). It is easily distinguished from sibling tools like open_tab or switch_tab, which have opposite or different actions.

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 tool's purpose makes its usage obvious (close a tab), but the description provides no explicit guidance on when to use it versus alternatives like switch_tab or list_tabs. There is no mention of exclusions or alternative scenarios, so it only gives implied usage context.

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