tabs_list

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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description reinforces "Read-only" while adding genuinely new context: the line-based output format, the current-tab marker, the fact that it launches the browser if needed (a real side effect of an otherwise read-only call), and the cross-tool data contract. It stops just short of mentioning timing (e.g., waiting for the page to be ready) or what happens when no browser is installed.

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?

Three tight sentences, front-loaded with the read-only guarantee and the resource, then the output contract, then the cross-tool routing. Every clause carries information an agent would otherwise have to discover empirically.

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 zero-parameter, no-output-schema list tool, everything an agent needs is present: what it returns, how to interpret the `*` marker, what to do with the ids, and what side effect to expect. Nothing essential 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 takes zero parameters, so the baseline is 4 and there is nothing the description could clarify beyond confirming the implicit scope of "connected browser." The schema is closed (additionalProperties: false), so no undocumented inputs exist.

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 ("list the open tabs of the connected browser") and goes further to specify the exact output shape: one tab per line as id, title, and URL, with `*` marking the current tab. That output contract lets an agent distinguish this from browser_status and snapshot without opening any 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?

Explicitly routes the agent: "Use the ids with tab_select, tab_close or any tool's `tab` argument" names the concrete consumers of this tool's output, and "For browser details as well use browser_status" names the sibling and when to prefer it. It even warns of the browser-launch side effect so the agent can anticipate state changes.

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