ui_invoke

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the annotations (destructiveHint=true, readOnlyHint=false), the description discloses additional behavioral context: it requires a user-enabled action tier and allowlist, returns action_denied if not permitted, and mandates user confirmation. It also clarifies that the action is a semantic click via UI Automation, providing richer operational expectations.

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 three sentences with no filler. The first sentence states the action and method, the second explains targeting and prerequisites, and the third gives an explicit user-confirmation requirement. All sentences contribute unique, actionable information and it is front-loaded with the core purpose.

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 click tool with four parameters, no output schema, and a destructive hint, the description covers the essential context: what the tool does, how to target elements, permission prerequisites and error case, and user confirmation. It is well-rounded and sufficient for an agent to know when and how to invoke it correctly, especially given the rich schema descriptions.

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 input schema has 100% description coverage for all four parameters, so the baseline is 3. The description adds meaningful semantics by explaining the targeting strategy: it can use name_contains or element_index from ui_find, linking element_index to a sibling tool. This clarifies how parameters relate and which combinations are relevant, going slightly 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?

The description uses a specific verb ('CLICK') and identifies the resource ('UI element') with the method ('via UI Automation'), and it lists element types (button, menu item, checkbox). It also distinguishes from sibling tools by referencing ui_find for element selection, making its role clear relative to related tools like ui_set_value and ui_find.

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 states when to use this tool (to click a UI element), how to target elements (name_contains or element_index from ui_find), and prerequisites (user-enabled action tier + allowlist) with the failure mode (action_denied). It also instructs to confirm with the user before acting. It does not explicitly say 'do not use for setting values or focusing windows,' but the clear verb and targeting guidance imply the scope.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.