Invoke a no-argument QML method or signal on a Cascadeur UI element—such as clicked, toggle, open, or close—when direct on-screen clicking is not possible.
Invoke a no-argument QML method or signal on an element, e.g. 'clicked', 'toggle', 'open', 'close'. Useful when an element cannot be clicked on screen.
| Name | Required | Description | Default |
|---|---|---|---|
| ref | Yes | Element ref from the latest ui_tree or dialogs result. | |
| method | 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. It usefully discloses the key behavioral constraint that the target method must take no arguments, but says nothing about side effects of invoking a signal, what happens if the method name doesn't exist, whether the ref must be fresh, or what is returned.
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: capability first, usage condition second. No filler, and the examples are embedded efficiently.
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, no-output-schema tool this is nearly sufficient: what it does, examples, and when to reach for it. The remaining gap is failure semantics – invalid refs or missing method names – which an agent would need to handle.
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 50% – 'ref' is documented in the schema while 'method' is a bare string. The description compensates for that gap by giving example method values and stating the no-argument restriction, adding real meaning beyond the schema.
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 ('invoke a no-argument QML method or signal on an element') and gives concrete examples of methods ('clicked', 'toggle', 'open', 'close'). It distinguishes itself from ui_click via the 'cannot be clicked on screen' clause, though it never contrasts with the sibling call_action, which sounds adjacent.
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?
Gives a clear triggering condition: use it when an element cannot be clicked on screen. It offers no explicit exclusions or guidance on when ui_click, ui_key, or call_action would be preferred instead, so it stops short of full routing guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.