check

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

With no annotations provided, the description carries the behavioral burden. It discloses the hidden-input fallback behavior ('clicks the visible text instead, like a person would') and states that the tool returns the new state and subsequent side effects. This goes meaningfully beyond a bare description.

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 sentences, each earning its place: the core operation, the hidden-input behavior, and the return value. The most important scoping information is front-loaded, with no filler or repetition.

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 low-complexity tool with two parameters and no output schema, the description covers how matching works, what interaction occurs, and what is returned. The phrase 'anything that followed' is slightly vague, and failure/not-found behavior is omitted, but these are minor gaps.

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%, so the baseline is 3. The description reinforces that matching is by visible label, but it does not add substantive detail about the parameters beyond what the schema already documents.

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 states a specific verb ('check or uncheck') with a specific resource ('checkbox or radio button found by its label'), and distinguishes itself from generic interaction by noting how hidden inputs are handled. This clearly separates it from siblings like click, fill, and select.

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 implies the right context: use this when the target is a checkbox or radio button identified by visible label. However, it never explicitly says when not to use it or names alternatives like click or select, so the routing guidance is only implicit.

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