click_at

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

No annotations are provided, so the description carries the full burden. It says nothing about side effects, whether permission or gating is required, or what happens on a page that cannot be clicked. Critically, the schema exposes an allow_writes flag defaulting to false, and the description never explains what that gate does or when it must be enabled.

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 sentences, front-loaded with the action, then the coordinate frame, then the use case. No filler and no repetition of the schema.

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 mutating click tool with no annotations, no output schema, and 0% parameter coverage, the description answers the most important question (what coordinate space) but omits the allow_writes gate and any statement of return/verification behavior. Adequate, not complete.

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 0% (bare titles only), so the description must compensate. It does define x/y meaningfully by tying them to the pixel space of the look() screenshot, but allow_writes — the one parameter with real behavioral consequence — is left completely unexplained.

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) plus the exact target (a point of the viewport) and the coordinate space (pixels of the screenshot from look()). It implicitly separates itself from the sibling 'click' by scoping to 'anything with no numbered element', though it never names that sibling outright.

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?

'For canvases, challenge widgets and anything with no numbered element' is an explicit when-to-use condition, and it implies the reciprocal condition for the numbered-element sibling. No hard exclusions or pitfalls are stated, but the routing intent is clear.

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