list_tabs

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

The description discloses that CDP provides fresh title/URL data and that it falls back to session file data, enriching with indices. This adds behavioral context beyond just listing and is transparent about data sourcing, especially with no annotations provided.

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?

Two sentences, front-loaded with the primary function, and each sentence adds value – no fluff. The structure efficiently conveys purpose and behavioral nuance.

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 0-parameter, read-only list tool, the description covers the output fields and data-freshness behavior. It does not specify the exact return format (e.g., array of objects), but is otherwise sufficient given no output schema or annotations.

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, and the description adds meaning by detailing the output fields (indices, URLs, titles, active state) and data source. With no parameters to document, the baseline is 4, and the description sufficiently compensates.

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 clearly states 'List all open tabs with indices, URLs, titles, and active state' – a specific verb and resource. It distinguishes from sibling tools that open/close/focus/move tabs by specifying a listing operation.

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 the tool is for enumerating tabs and gives no exclusions or alternatives. However, the purpose is clear enough that an agent can select it when needing an unfiltered list of open tabs; sibling tools are action-oriented, so context is clear.

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