ax_click

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

Describes behavior in detail: no cursor movement, background operation, case-insensitive substring matching, targets last-window-captured app, Windows UIA not implemented. No annotations provided, so description fully covers transparency.

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?

Efficient paragraph: first sentence core action, second explains query, third gives fallback. No redundant sentences.

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?

Covers all needed info for invocation: purpose, query format, target application, limitations, and fallback. Adequate for an action tool with one parameter and no output schema.

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?

Single parameter 'query' is described in schema; description adds examples and clarifies substring matching and case-insensitivity. With 100% schema coverage, description adds value via examples.

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?

Description states it presses a UI control via accessibility tree, without coordinates or cursor movement. Distinguishes from sibling tools like left_click by clarifying background operation.

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?

Explicitly says when to use (apps with accessibility tree) and gives fallback (screenshot + left_click on error). Provides clear context for selection.

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