list_tabs

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

No annotations are provided, so the description must carry the behavioral disclosure burden. It communicates the read-only nature implicitly ('List') and clarifies scope against sessions, but doesn't disclose output format, ordering, or whether it reflects live state vs cached state. For a read operation, the disclosure is adequate though minimal.

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?

Single sentence, zero waste. Every word earns its place, and the phrase 'currently controlled by this browser session' adds meaningful scope qualification beyond a generic 'list tabs'.

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 read-only listing tool with no output schema, the description is reasonably complete. It would benefit from mentioning what fields are returned per tab, but given the simple nature of the operation, the explanation is adequate. The sibling distinction (list_user_tabs) is the main context gap.

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 0 parameters with 100% schema coverage, so the baseline is 4 per the rubric. The description adds context about what 'tabs' means in this tool's scope (session-controlled), which clarifies the semantics of the implicit query being performed.

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 a clear verb+resource structure: 'List tabs currently controlled by this browser session.' It specifies the scope (session-controlled tabs) and distinguishes itself from the sibling tool list_user_tabs, which presumably lists tabs belonging to a different context/user.

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 gives clear context about scope ('currently controlled by this browser session') but does not explain when to prefer this over list_user_tabs or claim_tab. The distinction from list_user_tabs is implied by the phrase 'this browser session' but not made explicit with guidance on which to choose.

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