tap

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is largely covered. The description adds only the pixel unit; it says nothing about where the coordinate origin is, whether out-of-range coordinates error or are clamped, or whether the tap blocks until the UI settles — all relevant because the call mutates device state.

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?

One sentence, zero filler, and the key qualifier ('in pixels') is placed immediately after the action. Nothing is buried or redundant.

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?

An output schema exists so return values need no prose, but for a 3-parameter tool with 0% schema coverage the definition is under-specified: the serial parameter, coordinate origin, and error behavior are all absent. An agent can guess the happy path but not the edge cases.

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 description coverage is 0%, so the description must carry the burden, yet it only clarifies that x/y are pixels. The origin and axis direction are unstated, and 'serial' — the device selector on a multi-device tool — receives no explanation at all in schema or description.

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 ('touch the screen at a point') and adds the coordinate unit ('in pixels'), which implicitly separates it from element-based tapping. It does not name tap_element or otherwise call out the distinction, so the agent must infer it from the sibling list.

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?

There is no when-to-use guidance and no exclusion. With a sibling literally named tap_element, the single most important routing decision for this tool — coordinate tap vs. element tap — is left entirely to inference. Nothing indicates when a raw pixel tap is preferable or required.

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