activate_appBring any application to the foreground, launching it if necessary, so clicks and keystrokes are directed to it. Specify the app name to focus.
Bring an application to the front (launching it if needed) so subsequent clicks/keystrokes go to it. Give the app's name, e.g. 'Safari', 'Notes'.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Application name to focus. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds a behavioral detail beyond annotations: 'launching it if needed' discloses that the tool may start an application, which is a side-effectful action. Annotations already indicate readOnlyHint=false and destructiveHint=false, so the description supplements rather than contradicts, but it does not cover failure modes or permissions.
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 sentences with no filler: the first states the core behavior and secondary effect, the second gives a concrete usage instruction with examples. It is front-loaded and every word earns its place.
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 single-parameter tool with high schema coverage and annotations present, the description covers the main purpose, the side effect of launching, and the required input format. It could mention error behavior (e.g., app not found) but this is not critical for a simple activation tool.
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 100% for the single 'name' parameter, and the schema already states it is the application name to focus. The description adds examples and reinforces the input requirement, but this is marginal value on top of an already well-documented parameter.
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 clearly states the action ('Bring an application to the front') and the resource (an application by name), with examples 'Safari', 'Notes'. It also adds the launching side effect, which helps distinguish it from a pure focus operation, though it does not explicitly differentiate from siblings like open or run_applescript.
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 phrase 'so subsequent clicks/keystrokes go to it' implies when to use the tool, but there is no explicit guidance on when not to use it or which sibling tools (e.g., open, type_text) might be alternatives. Usage context is implied rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.