Fills and verifies up to 50 text fields on legacy IE-mode pages, using native or DOM input events and stopping on the first failure.
Fill and verify up to 50 text fields. Explicit mode=dom sends input/change events instead of native keyboard events. Stops on failure; no automatic retry or submit click. Page event handlers may submit. Never echoes values.
| Name | Required | Description | Default |
|---|---|---|---|
| mode | No | native | |
| fields | Yes |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden and does well: it discloses the event mode difference, stops on failure, no retry or submit click, possible page-handler submission, and that values are never echoed. It stops short of describing partial-fill state or verification output details.
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 four short sentences, front-loaded with purpose, then key behavioral caveats. Every sentence adds distinct information with no repetition or waste.
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 batch mutation tool with no annotations, no output schema, and 0% schema description coverage, the description covers important behavior but omits parameter structure and what 'verify' returns. It is adequate but leaves clear gaps an agent must infer.
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 compensate. It explains the 'mode' parameter's native-vs-dom distinction, but it does not clarify the 'fields' array structure, especially what 'ref' refers to and how values are matched to fields, leaving half the parameters underspecified.
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 states a specific verb and resource: 'Fill and verify up to 50 text fields.' The scope ('up to 50') distinguishes it from the single-field browser_fill, but it does not explicitly name or contrast with that sibling, which prevents a 5.
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?
Use for filling many text fields is implied by the description, but there is no explicit guidance on when to choose this over browser_fill or browser_select, nor any stated exclusions. The behavioral notes about mode and failure handling are useful but do not substitute for usage selection guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.