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

No annotations are provided, so the description must carry the behavioral disclosure burden. It states the action and the desktop-only scope, but does not disclose key behaviors such as whether typing replaces existing input, whether key events are dispatched, or what happens on selector failure. This leaves important behavioral uncertainty for a tool with zero annotation support.

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 exceptionally concise: one sentence for the primary purpose and one for the usage caveat. It is front-loaded with the core action and scope, with zero filler. Every phrase adds value.

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 three-parameter typing tool with no output schema, the description covers the essential context: what it does, where it operates (desktop grid browser), and how to obtain pageId (via web_navigate as stated in schema). It lacks some behavioral nuance like text replacement semantics, but the core operational context is sufficiently complete for correct 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?

Input schema coverage is 100% with descriptive parameter texts for pageId, selector, and text. The description does not add additional semantic nuance beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 states a specific verb and resource: 'Type into an element in the DESKTOP grid browser (by pageId)'. It explicitly differentiates from the device-based sibling webpage_type, and the mention of pageId versus udid further clarifies scope. An agent can immediately understand what this tool does and how it differs from related tools.

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 explicitly provides a when-not: 'NOT a device', and a clear alternative: 'to type on a real phone or tablet use webpage_type (by udid)'. This gives the agent an unambiguous decision rule for tool selection, covering both the negative case and the recommended alternative.

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