fill_form

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

Annotations already establish that this operation mutates state (readOnlyHint=false) and is non-destructive. The description adds valuable context the annotations do not cover: typed=True simulates human key-by-key input, which affects bot scoring; the default follows the humanize setting; and a submit click can be appended, which has its own side effect. It does not describe what happens when a selector fails or how navigation after submit behaves.

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 tight sentences, with the core operation and parameter map front-loaded before the optional behavior and the typed nuance. 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?

Since an output schema exists, return values needn't be explained, and the annotations cover the safety profile. The description still leaves error and partial-fill behavior and post-submit waiting unspecified, but everything needed to invoke it correctly is present.

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 has to carry the parameters, and it does: it gives the shape of fields, the optional-submit role of submit_selector, and the Boolean and default semantics of typed. The only gap is submit_selector's empty-string default and the 'ref' half of selector_or_ref.

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?

States a specific verb and resource: fill several inputs at once, driven by a {selector_or_ref: value} map, with an optional submit click. This bulk-fill scope separates it from the single-input siblings type_text and click, though those alternatives are never named.

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?

"Fill several inputs at once" implies that the single-field case belongs to another tool, and the submit_selector gives a clear optional action. However, no sibling is named and no prerequisites or exclusions are stated.

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