Move a tab into its own window

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

Annotations only declare readOnlyHint=false, so the description must carry the rest, and it does disclose the actual state change: the tab is removed from its current window and a new window is created to hold it. It stops short of saying whether the new window is focused, whether the tab becomes active there, or what happens to the source window if it empties.

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?

Two sentences with the core action front-loaded in the first; the API name in parentheses is useful grounding. The second sentence is slightly conversational but earns its place by supplying usage rationale.

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 one-optional-parameter mutation with no output schema, the definition covers what the tool does, the mechanism, and typical motivation. Remaining gaps (focus behavior, empty source-window handling, return value) are minor for an agent deciding whether to call it.

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% and the single optional 'context' parameter is documented in the schema, including the default-to-active-tab behavior. The description adds no extra semantics about the parameter, so the schema does the work and baseline 3 applies.

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?

States a specific verb and resource: take a tab out of its window and put it in a new window, backed by the named underlying API (gBrowser.replaceTabWithWindow). It clearly implies a distinct outcome from browser_move_tab (move within a window) and browser_split_view, but never names those siblings explicitly, so differentiation is left partly to inference.

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 second sentence supplies motivating scenarios (park a page on a second monitor, keep one page visible while working elsewhere), which implies when to reach for it. However, there is no explicit guidance on when NOT to use it and no named alternative for cases like moving a tab between existing windows or splitting a view.

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