Browser Form Fill

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

With no annotations, the description carries the full burden and does disclose meaningful behavior: it auto-picks the right interaction per element (text input/textarea typing, native <select>, checkbox/radio clicks) and interprets truthy values as 'check it'. It stops short of covering failure behavior (unmatched selectors), waiting, or whether existing values are cleared.

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?

Two sentences, front-loaded with a concrete example, then the per-element behavior and submit option. No filler or redundant restatement of the name.

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?

There is no output schema and no annotations, so the description is the only source of behavioral detail, yet it never says what the tool returns or how partial failures/selector misses are reported, which matters for an automated form fill with an optional submit.

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 100%, so the baseline is 3, and the description adds genuine semantics on top: the worked example clarifies the selector->value map shape and the truthy-value rule for checkboxes/radios is not captured in the schema. mode and submitSelector meaning still come entirely from the schema.

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 multiple form fields') and clarifies the distinguishing trait of batching 'in one call', which separates it from single-action siblings like browser_type and browser_select_option. The concrete example map makes the intended payload unambiguous.

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 'in one call' framing gives clear context for when to reach for this tool (filling several fields at once) and it explains the optional follow-up submit click. However, it never explicitly names alternatives such as browser_type/browser_select_option or states when not to use it.

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