browser_tabs

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

With no annotations, the description carries the full burden of behavior. 'List all' communicates a non-mutating, read-only operation and the parenthetical enumerates the fields returned. It doesn't describe edge cases like an empty no-tab state or whether the active tab is marked, but for a simple listing tool this is adequate disclosure.

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?

A single compact sentence with the operation front-loaded and the return fields in a clear parenthetical. No filler or redundancy.

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 parameterless listing tool, the description is nearly complete: it names the resource, scope, and return fields. It could explicitly state output shape or mention an empty result, but nothing required to invoke the tool correctly is missing.

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 tool has zero parameters, so there is no parameter burden to document. The description's parenthetical adds meaningful detail about what each tab entry contains, exceeding what the empty input schema provides.

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 uses the specific verb 'List' with resource 'all browser tabs' and names the returned fields (index, title, url, active). This clearly distinguishes it from sibling tools like browser_open, browser_switch_tab, or browser_snapshot that do different things.

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?

No when-to-use guidance is given. It doesn't mention that this tool is for inspection only, nor does it contrast with alternatives like browser_switch_tab for navigation or browser_snapshot for page content. The context is implied by the name, but there are no explicit exclusions or alternative conditions.

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