tab_list

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

With no annotations, the description carries the full burden of behavioral disclosure. 'List' clearly indicates a read-only operation with no side effects, which is useful. However, it does not mention ordering, whether hidden tabs are included, or any other behavioral nuances that could matter to an agent.

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, front-loaded sentence with no filler. It communicates the essence of the tool in five words and is easy to scan.

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 tool, the description is minimally sufficient to invoke it correctly. However, there is no output schema, and the description does not specify what information the returned list contains (e.g., tab IDs, titles, URLs), which an agent might need for downstream actions like tab_select.

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 are no parameter semantics to explain. Per the rubric, a zero-parameter tool earns a baseline of 4; the description adds nothing about parameters because none 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?

The description uses a specific verb ('List') and a clear resource ('all open tabs'), making the tool's function immediately obvious. It also distinguishes itself from sibling tab tools (tab_new, tab_select, tab_close) by focusing solely on enumeration.

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 intended use is implied: call this tool when you need to see the currently open tabs. However, there is no explicit guidance about when to prefer this over alternatives like tab_select or tab_close, nor any mention of context or prerequisites.

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