browser_tabs

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

Annotations already flag destructiveHint=true and readOnlyHint=false. The description lists both read-only (list, select) and destructive (create, close) actions, which is consistent but adds little beyond the annotations. It does not disclose important behavioral details such as that closing a tab may lose state, that creating a tab opens a default page, or that selecting a tab focuses it. The description carries minimal additional transparency given the annotation cues.

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 that efficiently enumerates the tool's capabilities. It is front-loaded with the operative verbs. While concise, it could be slightly improved by providing a brief example or clarifying purpose in a natural way. Still, it earns its place with no wasted words.

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?

Given the tool has three parameters including an enum and no output schema, the description is insufficiently complete. It does not explain what 'list' returns (e.g., an array of tab objects), what 'select' does (focus the tab), or what happens when closing without index. These are essential for an agent to invoke the tool correctly. The schema partially compensates, but the description should fill gaps that the schema does not cover.

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 input schema already provides 100% coverage: action with enum descriptions, url for 'new', index for 'close/select' with a note on default close behavior. The tool description merely repeats the action list without adding any new meaning or clarifying parameter semantics (e.g., format of url, bounds of index). Since the schema does the heavy lifting, a baseline score of 3 is appropriate.

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 explicitly lists the four operations (list, create, close, select) on the specific resource 'browser tab'. This clearly distinguishes it from all sibling tools, which cover other browser actions like navigation, clicking, and form filling. The verb-resource combination is precise and unambiguous.

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 implies that this tool is for managing tabs—listing, creating, closing, or selecting them—but it does not explicitly state when to prefer this over other tools. For example, it doesn't mention that closing a tab differs from closing the entire browser (browser_close) or that selecting a tab is not the same as navigating. There is no when-not-to-use guidance or comparison with alternatives.

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