new_firefox_window

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

No annotations are provided, so the description must carry the behavioral burden. It discloses that focus isn't stolen by default and that the window is verified, but omits details like what happens if the URL is invalid or what the verification process entails. It provides some useful context but lacks depth.

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 one clear, front-loaded sentence, with no redundancy. It quickly covers purpose, optional URL, focus behavior, and return value without waste.

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 is simple with only two optional params and no output schema; the description covers the action, focus behavior, and return value. It lacks a bit on error cases but is adequately complete for low complexity.

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 100% for the two params; the description adds the 'without stealing focus by default' nuance, which clarifies the 'active' param, but doesn't add syntax or format beyond the schema. Baseline 3 is appropriate.

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 verb and resource: 'Open a new Firefox window' and specifies optional URL and focus behavior. It distinguishes this from sibling tools like open_firefox_tab by targeting a new window rather than a 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?

The description implies when to use it (to open a new window) and that it can take a URL, and mentions the optional active parameter. It doesn't explicitly exclude alternatives like open_firefox_tab, but the purpose is clear enough for selection.

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