Click-Tool

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

No annotations are provided, so the description carries the disclosure burden. It clearly communicates a tap action at exact coordinates, but does not describe side effects, prerequisites, or what happens after the tap. For a simple input tool this is adequate, though more behavioral context could be added.

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 with no filler. The core action is front-loaded, and the routing guidance is placed second. Every phrase 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 two-parameter, no-output-schema tool, the description covers the essential information: what it does, how parameters relate to coordinates, and when to use a sibling instead. Minor omissions like coordinate origin or missing coordinate behavior prevent a perfect score.

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 0%, so the description must compensate. It adds meaningful semantics by identifying x and y as pixel coordinates, clarifying that these are screen-space positions rather than logical labels. It does not detail origin or bounds, but the core meaning is clear.

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 states a specific verb ('Tap') and resource ('exact (x,y) pixel coordinates'), and immediately distinguishes the tool from Click-By-Label by mentioning the alternative. This makes its function unambiguous relative to siblings.

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 explicitly states when to prefer an alternative: 'Prefer Click-By-Label when you have a label index from State-Tool.' This provides a clear when-not condition and names the alternative tool.

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