fill_form

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

No annotations exist, so the description carries full burden. It discloses key behaviors: partial errors do not abort, each field reports its own status, supports multiple input types, and prefers ref over selector. Could be improved by mentioning what happens after filling (e.g., form submission), but that's not critical for a fill action.

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 tight and well-structured: opens with the core purpose, then specifies how to use parameters, lists supported control types, gives usage guidance and error recovery steps. No extraneous words.

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 that fills forms with one call, the description covers all necessary aspects: input specification, behavior on partial errors, retry strategy, and warnings against using evaluate. Even without output schema, the agent has enough context to use the tool correctly.

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 coverage is 100% but description adds significant value: explains that each field requires ref or selector plus value, clarifies value types for different controls, and recommends ref as preferred. Also notes minItems constraint implicitly. This goes beyond the schema's descriptive properties.

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 action ('fill a complete form'), the resource ('form'), and positions itself as the preferred method for forms with 2+ fields. Distinguishes itself from siblings like 'type' and 'evaluate' by explicitly saying to use it instead.

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 explicitly tells when to use (forms with 2+ fields) and when not to (avoid multiple type calls or evaluate). Provides clear alternative actions for error recovery: call view_page and retry failing fields, and warns against using evaluate directly.

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