Focuses an application window by class name or title substring, enabling targeted switching on a Hyprland desktop.
Focus a window by its class name or title substring
| Name | Required | Description | Default |
|---|---|---|---|
| class | No | Window class to focus (e.g. 'firefox', 'kitty') | |
| title | No | Window title substring to focus |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already state readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is mostly covered. The description adds little beyond that: it does not explain what happens if no window matches, how multiple matches are resolved, whether focusing also switches workspaces, or whether the class and title filters are combined with AND/OR. For a state-changing focus operation, these are meaningful gaps.
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 description is a single front-loaded sentence with no filler. Every word contributes to stating the action and matching basis, making it as concise as possible for this tool.
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 two-parameter mutation tool with no output schema, the description is too thin. It omits whether at least one of class or title is required in practice, what happens with zero parameters, ambiguity when multiple windows match, and any side effects such as workspace switching.
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%, and the schema already documents both class and title with examples. The description only restates that windows can be matched by class name or title substring, adding no new meaning about combination logic or required combinations. Baseline 3 applies when the schema does the heavy lifting.
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 names a specific verb and resource: focus a window. It is distinguishable from siblings such as close_window, kill_window, list_windows, and get_focused_window. It does not explicitly name or differentiate against those siblings, so it falls short of a 5.
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 offers no explicit guidance on when to use this instead of get_focused_window or list_windows, nor any prerequisites. The only implied usage is that it is for changing window focus, which is not enough to guide tool selection reliably.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.