ff_open_tab

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

No annotations are provided, so the description carries the burden. It mentions the need for a running real Firefox with bridge add-on, which is a key behavioral prerequisite. However, it does not disclose other behavioral traits such as error handling, whether the tab is opened in background or foreground, or if it returns any result.

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 concise with two sentences. The first sentence front-loads the action. It could benefit from a slightly more structured format, but it is not verbose.

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 tool with two optional parameters and no output schema, the description is incomplete. It does not explain what happens if no url is provided, how the 'active' flag works, or any return value. Given the many sibling tools, more context on when to use this specific tool would be beneficial.

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. It does not describe the two parameters (url and active) at all, leaving the agent without context on how to use them. The parameter 'active' is particularly unclear without explanation.

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 action ('Open a new tab'), identifies the specific resource ('your real Firefox'), and distinguishes from siblings like 'open_tab' by emphasizing 'real' and the required bridge add-on.

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 for real Firefox with bridge add-on, but does not explicitly state when to use this tool versus alternatives like 'open_tab' for simulated browsers. There is no guidance on prerequisites or when not to use.

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