browser_type

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

With no annotations, the description carries the burden and delivers key traits: the value is set atomically rather than typed, keystroke handlers do not fire, and the two browser contexts ('main'/'support') share nothing. It still omits failure behavior (missing selector, timing/waiting), so not a full 5.

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?

Front-loaded with the core action and the replacement semantics, then the alternative, then the browser-scope caveat. Every sentence earns its place, though the phrasing is slightly prose-heavy for the small amount of information conveyed.

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?

Output schema exists, so return values need not be explained. For a browser-automation input tool the description covers mechanism, alternative, and context isolation, but leaves selector syntax and error/timing behavior unspecified.

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 0% across 3 params, so the description must compensate. It explains the `browser` parameter well (defaults to `main`, `support` is isolated, no shared state) but adds nothing about `selector` syntax or `text` semantics, which remain undocumented everywhere.

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 action and resource ('Fill a field, replacing whatever it holds') and immediately contrasts the mechanism with key-by-key typing. An agent can distinguish it from browser_press_key and browser_click without opening any schema.

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?

Names the explicit exception and the alternative for it: fields needing per-keystroke handlers (autocomplete) should 'click the field and use browser_press_key'. That is a when-not plus a named sibling, not just implied context.

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