check

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

Annotations are absent, so the description carries the full burden of behavioral disclosure. It only states the action without describing side effects, state changes, prerequisites, or failure cases. For example, it does not specify whether the target must already be visible or enabled, what happens if the target is not a checkbox/radio, or any permission or session dependencies. The minimal text does not meaningfully reveal behavior beyond the basic intent.

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?

The description is a single, taut-but-concise sentence with no filler or repetition. It gets straight to the point and is appropriately sized for the simple action the tool performs. It does not waste words, though a slightly longer version could add clarity without becoming 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?

Given the simple tool (no output schema, no annotations, 100% schema coverage), the description is thin on operational details. The agent cannot tell whether the tool can handle already-checked controls, what 'checking' does to a radio that is already checked, or how it differs from a generic click beyond the label. The absence of usage guidance and behavioral nuances makes it incomplete for correct invocation without assumptions.

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?

The input schema has 100% coverage with each parameter well described ('target' as '@eN or selector', 'session' guidance, and 'lease' context). The description adds no parameter-specific meaning (it only mentions the target type globally). According to the rules, with high schema coverage, the baseline is 3, which is appropriate.

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?

The description 'Check a checkbox / radio' clearly states the specific action (check) and the resource types (checkbox/radio). It distinguishes itself from the sibling 'uncheck' by implying a positive action, and from generic actions like 'click' by naming the element types. It does not explicitly contrast with alternatives, but the verb-resource pairing is specific enough for an agent to understand the tool's purpose.

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 description provides no guidance on when to use this tool versus alternatives. It does not mention that it is for checkbox/radio inputs only, nor does it advise avoiding it for other elements, nor does it reference the sibling tools (e.g., 'uncheck', 'click', 'toggle' not present). The agent is left to infer the preconditions and scope from the schema and name alone.

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