ui_set_value

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

Discloses that out-of-range values return a structured failure response instead of an exception, adding behavioral insight beyond the minimal annotation (openWorldHint: false).

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?

Concise, well-structured description with a clear purpose line followed by note on error handling and parameter list. Every sentence adds value with no redundancy.

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 two-parameter tool with no output schema, the description covers purpose, behavior, and parameters completely, leaving no obvious 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 has no descriptions (0% coverage), so the description adds essential meaning: automation_id is the element's identifier and value must be within the element's range. Could be more explicit about obtaining automation_id.

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?

Clearly states the tool sets a numeric value on specific UI elements (slider, spinner, progress bar) via RangeValuePattern, distinguishing it from other UI interaction tools.

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?

Specifies the intended elements and pattern, implying usage context. Lacks explicit when-not-to-use or alternative tools but provides sufficient guidance for appropriate selection.

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