get_current_window

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

With no annotations, the description carries the full behavioral burden and does well: it says the tool reads without focusing or changing the window, and it explains profile-local ID scoping. It could add edge-case behavior, such as what happens if no window is focused, but the non-mutating and scoping semantics are clear.

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 scope and non-mutating behavior are front-loaded, followed by precise routing to alternatives and the required profile prerequisite. The four sentences are compact and each contributes necessary context.

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 description is complete for this read tool: it covers purpose, alternatives, non-mutating behavior, the required profile_id source, and profile-local ID constraints. An output schema exists, so return values do not need to be explained in prose.

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 only 50%, but the description compensates for the undocumented required profile_id by explaining where to obtain it and warning that object IDs are profile-local. It also clarifies that populate controls whether tabs are included, though it adds little beyond the schema for that optional boolean.

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 uses a specific verb and resource: reading the profile's current, most recently focused Firefox window. It also explicitly distinguishes this from get_window and list_windows, so an agent can select it without opening sibling schemas.

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?

It states exactly when to use this tool and names concrete alternatives: get_window for a known window_id and list_windows to inspect all windows. The profile prerequisite is also called out explicitly.

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