Selects a GUI window by its current ID, making it the target for subsequent actions and observations. Coordinates in later inputs are interpreted relative to this window.
Select a window by current ID. Subsequent actions and observations target it; input coordinates are relative to it.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Current ID from glass_list_windows; re-list after window changes. |
Changes observed during successful MCP inspections.
v1.8.0Input schema / properties / id / descriptionPrevious value: -"The window id from `glass_list_windows`. Ids are not stable across calls —\nre-list rather than caching them."New value: +"Current ID from glass_list_windows; re-list after window changes."v1.2.0Input schema / titleRemoved value: -"SelectWindowArgs"v1.1.0v1.0.3v1.0.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations, the description discloses a meaningful behavioral trait: selection is stateful and influences all later actions and observations, including coordinate interpretation. This is useful context that annotations alone do not provide.
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 short sentences deliver the core purpose and the key behavioral consequence with no filler. The most important information is front-loaded.
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-parameter selection tool with rich annotations and full schema coverage, the description covers what selection does, how it affects subsequent operations, and how coordinates are interpreted. No critical operational detail is missing.
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?
The schema already fully documents the single 'id' parameter, including that it comes from glass_list_windows and should be re-listed after window changes. With 100% schema coverage, the description does not need to add parameter details, and its 'current ID' mention is consistent but not additive.
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 states a specific action ('Select a window'), a specific resource ('window'), and the key qualifier ('by current ID'). It also explains the consequence of selection, which distinguishes this from listing or inspecting windows among the sibling tools.
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 clearly indicates when the tool matters: before subsequent actions and observations, and when input coordinates should be interpreted relative to the selected window. It does not explicitly name alternatives or exclusions, but the usage context is unambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.