tap

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

The description adds no behavioral detail beyond what annotations already convey (readOnlyHint=false). It does not disclose potential side effects, failure conditions, or what the tool returns after execution, leaving the agent with minimal insight into the action's behavior.

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 a single concise sentence with no unnecessary words. It front-loads the verb and resource, making it immediately scannable and efficient for such a simple tool.

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?

Given the tool's simplicity (two required coordinate parameters, no output schema), the one-line description is minimally adequate. However, it lacks any mention of return values or failure modes, and does not differentiate from sibling input tools, making it less complete for an agent that must decide among alternatives.

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 schema coverage is only 33% (only device_serial has a description), so the description should compensate. The phrase 'absolute screen coordinate' clarifies that x and y represent absolute coordinates, adding meaning beyond raw integers. However, it does not explain coordinate origin or units, and device_serial's description is already in the schema, so the overall compensation is partial.

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 'Tap an absolute screen coordinate' uses a specific verb (Tap) and resource (screen coordinate), making the purpose immediately clear. The addition of 'absolute' distinguishes it from relative gestures like swipe, providing clear scope.

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?

No guidance is provided on when to use this tool versus alternatives like swipe, press_key, or type_text. There is no mention of prerequisites (e.g., screen on) or exclusions, leaving the agent to infer usage from the name alone.

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