tap

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

No annotations are provided, so the description bears the full burden. It usefully contrasts the exact-point tap with tap_element's randomized interior point, but says nothing about whether the tap blocks, whether it verifies the result, or what happens on a miss. The schema does document the verify/verify_poll_ms/verify_timeout_ms behavior, which partially compensates, but the description itself adds limited behavioral context.

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 tight sentences, no filler, with the core action and coordinate convention front-loaded and the sibling routing at the end. Every clause 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 5-parameter action tool with no output schema and no annotations, the description covers the essentials: what it does, coordinate convention, where to get coordinates, and when to use the sibling instead. Only the verification/wait behavior is left implicit and handled by the schema rather than the prose.

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 100%, so the baseline is 3. The description still adds value beyond the schema by clarifying that coordinates are pixels with origin at top-left, which the 'X coordinate in pixels' schema text does not establish, and by pointing to get_screen_state as the source of valid values.

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 ('Taps at the given screen coordinates') and pins down the coordinate semantics ('pixels, 0,0 = top-left'). It also distinguishes itself from the sibling tap_element, so the agent can separate the two without opening either schema.

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 where to get input ('Read coordinates from get_screen_state bounds') and names the alternative with the condition that selects it ('Prefer tap_element when you have a node's bounds'). Both when-to-use and when-to-prefer-another are stated.

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