open_tab

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

Without annotations, the description provides valuable behavioral details: it makes the tab active, and explains the profile behavior (copy of real cookies/sessions or clean browser). This goes beyond the basic schema, though it could elaborate on side effects like handling existing tabs.

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 concisely written with two sentences. The first sentence front-loads the core action, and the second sentence provides essential parameter guidance. No unnecessary words or repetitions.

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?

Given the tool's simplicity (two optional parameters, no output schema), the description covers the main use case and parameter behavior. It could mention error conditions or interactions with other tools, but overall it is adequately complete for an agent to use correctly.

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 schema coverage is 0%, so the description compensates by explaining the 'url' as optional navigation and the 'useProfile' parameter's effect. This adds meaningful context beyond the schema's type definitions, though the exact format or consequences of omitting parameters could be clearer.

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 the tool's action: 'Open a new tab' and optionally navigate to a URL, making the active tab. This distinctively describes the primary function and differentiates it from sibling tools like 'close_tab' or 'switch_tab'.

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?

While the description explains the optional 'useProfile' parameter and its effect (using a copy of cookies vs. clean browser), it lacks explicit guidance on when to use this tool compared to alternatives like 'ff_open_tab' or 'navigate'. No when-not-to-use scenarios are mentioned.

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