browser_fill_form

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

With no annotations provided, the description bears full responsibility for behavioral disclosure. It fails to mention key traits like whether existing field values are cleared, if missing fields cause errors, or if form submission occurs. This leaves significant uncertainty.

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 extremely concise (one sentence) and front-loaded with the core action. However, it sacrifices essential details, making it too brief for practical use. A little more structure (e.g., brief parameter hints) would improve clarity.

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?

Given the tool's complexity (nested array parameter, no annotations, no output schema), the description is insufficient. It provides no information on success/failure behavior, error handling, or return format, leaving the agent without critical context for robust invocation.

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?

The input schema defines a complex 'fields' array with multiple identification properties (ref, name, role, text, selector) and required 'value'. The description offers no explanations for these fields, leaving the agent to infer how to target form elements despite 0% schema description coverage.

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 'Fill multiple form fields at once' clearly states the action (fill) and resource (form fields), specifying it handles multiple fields simultaneously. This distinguishes it from sibling tools like browser_check (single checkbox) or browser_select_option (single dropdown).

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 implies use for batch form filling, and sibling tool names suggest alternatives for individual interactions. However, no explicit guidance on when to use or avoid this tool is provided, leaving some ambiguity.

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