chrome_type

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

With no annotations, the description carries the full burden. It discloses that it handles any language and emoji, which is a meaningful behavioral trait. Yet it omits details such as error handling (invalid index, no focus), potential side effects (e.g., form submission), and whether it operates on a specific tab/device. This is partial disclosure but not comprehensive.

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 two concise sentences with no redundancy. It front-loads the core action and then provides the key usage detail (index or focus) and a differentiator. Every word earns its place.

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 simple typing tool, the description covers the primary usage and intent. However, it lacks detail on error conditions, parameter semantics for device/tab_id, and any return values (though an output schema exists). With no annotations and zero schema descriptions, the tool is not fully self-explanatory for an agent, especially regarding optional parameters.

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%, so the description must explain all parameters. It explains 'text' (the content to type) and 'index' (field number from chrome_read), but provides no guidance on 'device' or 'tab_id' — these remain undocumented. Given the low coverage, the description does not fully compensate, leaving two parameters ambiguous.

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 (type into a field) and the resource (Chrome), and it explicitly differentiates from the phone's own keyboard (type_text) by noting language/emoji support. This makes the tool's purpose unambiguous even among many Chrome-related siblings.

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 provides concrete usage instructions: how to specify the field via an index from chrome_read, or omit it to type into the focused element. It also contrasts with the phone keyboard, hinting at when to prefer this tool. However, it does not explicitly mention when NOT to use it (e.g., for non-Chrome fields) or any prerequisites like having a tab open.

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