Browser Tab List

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description only says it lists tabs with URLs; it doesn't disclose whether it returns tab IDs, active tab status, or whether it creates a session if none exists. For a read-only listing tool, the lack of detail about the output structure and side effects is a gap, though the operation is inherently low-risk.

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 concise sentence that front-loads the action and resource. It is appropriately sized for a simple tool. It could add a bit more detail about the output, but it doesn't waste words.

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?

The tool has an output schema, so return values are presumably documented there. The description is minimal but sufficient for a simple listing operation. However, with no annotations and no usage guidance, an agent might not know whether the session parameter is required or what happens if the session doesn't exist. Given the tool's simplicity, this is a minor gap, but the description could be more complete.

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?

Schema description coverage is 0%, so the description must compensate. The description mentions 'a session' which maps to the 'session' parameter, but it doesn't explain the default value behavior or what values are valid. The parameter is optional with a default, so the description's mention of 'a session' is adequate but minimal. Baseline 3 is appropriate because the description adds some context but doesn't fully explain the parameter semantics.

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 states a specific verb ('List') and resource ('tabs of a session') and mentions the output includes URLs. It is clear what the tool does. However, it doesn't explicitly distinguish itself from sibling tools like browser_tab_new, browser_tab_select, or browser_tab_close, though the name and description make the distinction fairly obvious.

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 usage: call this when you need to see the tabs in a session. It doesn't explicitly state when to use it versus alternatives like browser_tab_select or browser_session_list, nor does it mention any prerequisites (e.g., a session must exist). The context is clear enough for a simple listing tool, but there is no explicit guidance.

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