windowsLists open GUI app surfaces on a nested Wayland display with IDs, titles, classes, geometry, focus, and PIDs, helping agents target screenshots and input without guessing.
Lists windows inside the display: id, title, app_id/class, shell (xwayland or xdg_shell), rect, focus and pids. Rects are in output coordinates, matching screenshots.
| Name | Required | Description | Default |
|---|---|---|---|
| id | No | Display id from display_open. Optional when exactly one display is open. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations at all, the description carries the full burden, and it does add real context by disclosing the returned fields and clarifying that rects are in output coordinates matching screenshots — a genuinely useful behavioral note. It still omits whether a display must be open, result ordering, whether hidden/minimized windows are included, and whether the call blocks or is instant.
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 dense sentences with zero filler: the first defines the payload, the second resolves the most likely ambiguity (coordinate space) up front. Nothing repeated from the schema or title.
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?
There is no output schema, so the description compensates by enumerating the returned fields and pinning down the coordinate system — enough for an agent to consume results correctly. Only minor gaps remain around display preconditions and result ordering.
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 description coverage is 100% for the single optional 'id' parameter, and the schema already explains the 'optional when exactly one display is open' fallback. The description adds nothing about the parameter, so 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 ('Lists windows inside the display') and then enumerates exactly what each entry contains (id, title, app_id/class, shell, rect, focus, pids). An agent can tell this is an enumeration tool rather than an action tool, though it doesn't explicitly contrast itself with siblings like wait_for_window or screenshot_window.
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?
Usage is only implied: the field enumeration suggests 'call this to discover windows before acting on them', but there is no explicit when-to-use, when-not-to-use, or alternative named. The relationship with wait_for_window (polling vs one-shot listing) is left to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.