window_closeCloses a specified window by asking the compositor to act as if its close button was clicked; provide the window ID to dismiss it programmatically.
Asks the compositor to close a window (as if clicking its close button).
| Name | Required | Description | Default |
|---|---|---|---|
| id | No | Display id from display_open. Optional when exactly one display is open. | |
| window_id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose the important semantics: this is a polite request to the compositor equivalent to a close-button click, implying the app may prompt or refuse. It says nothing about whether the call blocks until the window disappears, how refusal or a missing window is reported, or whether it is reversible.
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?
One front-loaded sentence with a high-value parenthetical and zero filler. Nothing could be removed without losing meaning.
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 two-parameter GUI action with no annotations and no output schema, the description covers what the action does and its graceful-close nature, which is the core need. It is still incomplete on the undocumented 'window_id', on whether the call waits for the window to disappear, and on failure behavior.
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%: the display 'id' is described in the schema, but 'window_id' is an undocumented integer in both schema and description. The description adds no parameter meaning at all, so it fails to compensate for the coverage gap.
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 ('close a window') and adds the mechanism ('asks the compositor... as if clicking its close button'), which separates it from display_close in spirit. It doesn't explicitly name display_close or a force-kill sibling, so the differentiation is implied rather than stated.
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?
There is no when-to-use guidance: nothing says whether to prefer this over display_close, whether a window must be focused first, or what to do if the app refuses to close. The parenthetical hints that this is a graceful request rather than a forced termination, but that is behavioral detail, not usage routing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.