set_value

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

With no annotations, the description carries the behavioral burden and covers key runtime behavior: the default 7-second timeout when timeout is 0/None and the exception on element-not-found. It leaves the event behavior of direct value setting unstated, but 'directly' hints that it bypasses keystroke simulation.

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 short sentences, front-loaded with the main action and each sentence adding distinct information: purpose/examples, timeout default, and failure behavior. No filler.

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 simple 3-parameter tool, the description supplies the essential action, a default, and the error case, and the output schema covers return expectations. It is only mildly incomplete in not addressing how set_value relates to typing/sibling functions.

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 0%, so the description must explain the parameters; it does address timeout with a concrete default rule. It does not explain what selector should select or how text maps to the value being set, leaving both required parameters to be guessed.

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 action ('Set an input's value directly') and clarifies with concrete examples (sliders, fast form fills). It does not explicitly differentiate from sibling type_text or send_keys, but the direct-assignment phrasing makes the core purpose distinct.

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?

It gives context for when to use the tool through examples ('for sliders, fast form fills'). However, it never names alternatives like type_text or send_keys or states when not to use set_value, so the selection rule is implied rather than explicit.

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