open_firefox_tab

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

With no annotations, the description carries the full burden. It discloses useful behavioral traits like the tab being inactive by default and returning verified IDs, but it does not explain what 'verified' means, potential failure modes, permission requirements, or side effects beyond the obvious tab creation.

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 that wastes no words. It packs the core action, URL constraint, default behavior, and return values into a compact and readable form.

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 simple tool with no output schema, the description adequately covers the main behavior and return values. It does not explain what happens if windowId is omitted, but the schema's property descriptions fill that gap. The meaning of 'verified' could be clearer, but overall the description is sufficient.

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 coverage is 67%, with url lacking a description. The description adds important meaning by restricting url to 'explicit http:// or https://', which is beyond the schema's 'uri' format. The active and windowId parameters are already documented in the schema, and the description provides no extra nuance for them.

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: opening an explicit http:// or https:// URL in Firefox. It also adds specific scope details ('inactive by default') and return value ('verified tab ID and window ID'), which distinguishes it from sibling tools like list_firefox_tabs or create_firefox_tab_group.

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 opening a Firefox tab with a URL and notes the default inactive behavior, but it does not explicitly state when to prefer this tool over alternatives or when not to use it. No alternative tools are mentioned, so the guidance is only implicit.

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