browser_fill

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

With no annotations, the description carries full burden for behavioral disclosure. It only states the basic fill operation but does not mention side effects (e.g., clearing the field, triggering events), behavior on missing selectors, or whether it replaces existing text. The clear_first parameter is not mentioned, so the agent is unaware of the default clearing behavior.

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 a single, efficient sentence with no fluff. It is front-loaded with the action and key parameters. However, it could be slightly more structured to include parameter details without losing conciseness.

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 simplicity of the tool, the description is still incomplete. It lacks information about the optional clear_first parameter, error handling, and differentiation from siblings like browser_type. With no output schema and no annotations, the agent has insufficient context to call the tool reliably.

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 schema has 0% description coverage, so the description must compensate. It explains selector and text implicitly but omits clear_first entirely. It also does not specify selector syntax (CSS, XPath) or any constraints on text. This leaves a required parameter undocumented in any form.

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 clearly states the action (fill), the resource (an input matched by selector), and the payload (text). It is a specific verb+resource but does not distinguish from sibling browser_type, which might also interact with inputs. Still, the purpose is 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?

No guidance is given on when to use this tool versus alternatives like browser_type. There is no mention of context, prerequisites, or exclusions, leaving the agent to infer usage.

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