type

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

Annotations only declare openWorldHint, so the description carries the behavioral load and does disclose two valuable traits: default replacement semantics and 'The typed text is never echoed,' which tells the agent it cannot verify input from the response. It omits failure behavior (element not found, timeout) and whether submit can trigger navigation, which matter for an open-world browser action.

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?

One dense sentence with semicolon-separated clauses; the core action and its default are front-loaded, and modifiers follow in the order an agent would consider them. Slightly telegraphic, but no clause is 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?

No output schema exists, and the description compensates by noting the silent-input behavior so the agent knows to verify state another way (e.g. snapshot/read). For an 8-parameter open-world action it is largely complete, with only failure and post-submit side effects left unstated.

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 coverage is 50%; the undocumented parameters are exactly text, append, slowly and submit, and the description defines all four in prose, including the default (replace) that the schema leaves unstated. It adds no detail for target, tab, snapshot or timeout_ms, but those already have schema descriptions.

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 ('Type text into a field') plus the accepted field kinds (input, textarea, contenteditable). It does not explicitly distinguish itself from the sibling fill_form or press, so the agent must infer the boundary from names alone.

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?

Gives conditional guidance for each behavioral mode: append for adding, slowly for autocomplete widgets, submit to press Enter afterwards. No explicit when-not-to-use or named alternative (e.g. fill_form for multi-field entry, press for bare keystrokes) is given.

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