fx_select

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

With no annotations, the description carries the behavioral burden, and it does state the core action and selection mechanism. However, it does not disclose side effects (e.g., change/input event dispatch), behavior when no matching option exists, or whether it waits for re-render. This is minimum viable but not rich.

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 front-loaded sentence with no filler or redundancy. Every word contributes to the core meaning.

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 tool with four undocumented parameters, no output schema, and no annotations, a one-sentence description is not enough. The agent still lacks the semantics of ref and selector, any return-value expectation, and any guidance on selecting between label/value.

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 four parameters. It gives meaning to 'label' and 'value' ('option value or visible label') but leaves 'ref' and 'selector' entirely unexplained, forcing the agent to guess their roles.

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 names a specific verb ('Set'), a concrete resource ('<select>'), and the two selection criteria ('option value or visible label'). This is enough to distinguish fx_select from interaction siblings like fx_click, fx_type, and fx_toggle, which target different controls.

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?

There is no guidance about when to use this tool instead of alternatives, no mention of when label vs value should be preferred, and no exclusions or prerequisites. An agent is left to infer that it is for select elements from the description alone.

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