phone_tap

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

Annotations already declare destructiveHint=true, idempotentHint=false, readOnlyHint=false and openWorldHint=true, so the safety profile is covered. The description adds the useful workflow constraint that tapping should be followed by an observation to verify, but says nothing about what the tap affects or failure 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?

A single compact sentence that front-loads the action and appends the verification step; no filler. It is short to the point of under-specification rather than verbose.

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 explanation, and annotations cover the mutation/safety profile. However, with 0% schema description coverage the description should have documented the serial parameter and coordinate expectations, which it does not.

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 parameter meaning. It conveys that x/y are screenshot pixel coordinates, which is genuine added context, but the serial parameter (device targeting) is never mentioned and no coordinate format/ranges are clarified.

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?

Specific verb (tap) plus resource (screenshot coordinates), with a verification step appended. It implicitly separates itself from phone_tap_element by stressing coordinate-based tapping, though it never names that sibling explicitly.

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 phrase 'observed native screenshot coordinates' implies a prerequisite workflow (screenshot/observe first) and 'then observe to verify' gives a follow-up, but there is no explicit when-to-use vs when-to-prefer phone_tap_element guidance or exclusions.

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