click

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

With no annotations, the description carries the full behavioral burden and does so well: it discloses a safety gate (native confirmation shown to the human for irreversible-sounding controls like Send, Pay, Delete, Submit) and the exact failure mode (refused if declined or timed out). It also states the return shape (RESULT line with ok or ERROR plus reason) and that a fresh observation follows, so no separate observe call is needed.

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?

Three tight sentences: capability first, target classes second, safety and return behavior third. The parenthetical examples (Send, Pay, Delete, Submit) are illustrative rather than filler, and nothing is repeated unnecessarily.

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 one-parameter action tool with an output schema available, the description covers everything an agent needs: what it acts on, which controls it suits, the confirmation/refusal policy, and that the observation is refreshed automatically. Missing details such as navigation waiting or disabled-element behavior are minor at this complexity.

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 100% and the single ref parameter is already documented with the same examples and the renumbering caveat. The description adds no syntax, format, or semantic detail beyond what the schema provides, so the baseline 3 applies.

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 (click), scoped to exactly one element by ref, and distinguishes the two backends it can act on: a page element through the DOM versus a native control through UI Automation. An agent can separate this from siblings like press, type_text or scroll without opening any 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?

Gives concrete context for use — buttons, links, checkboxes, menu items, list items and tabs — which tells the agent the intended target classes. It stops short of explicitly naming alternatives or stating when not to use it (e.g. keyboard activation via press, or typing into fields via type_text), so routing is implied rather than specified.

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