type

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

Annotations already declare destructiveHint=true and openWorldHint=true, so safety is partially covered; the description adds genuine behavioral context by flagging the ASCII/US-layout restriction (non-ASCII input is a risk) and that the host clipboard is untouched. It does not say what happens on non-ASCII input, whether Enter is pressed, or how focus is established, so behavior under failure stays opaque.

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?

Two sentences, front-loaded with the action and immediately followed by the distinguishing constraint. Nothing is redundant or padded relative to a one-parameter tool.

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?

A simple tool with no output schema, so return values need no explanation. However, given destructiveHint=true, the description should clarify the irreversible side effects (typing into a focused app can submit commands) and the focus precondition; both are left implicit.

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?

With a single parameter at 0% schema description coverage, the description supplies the key semantic: the text must be US-layout ASCII, which is essential for correct invocation. The schema's maxLength of 20000 is not echoed or explained in the description, leaving chunking behavior for long text unaddressed.

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 concrete verb and target: 'Type US-layout ASCII into the guest's focused application,' and adds a negative scope claim ('Does not use the host clipboard') that distinguishes it from a paste-style operation. It stops short of distinguishing it from the sibling 'key' tool, which is the nearest ambiguity.

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?

Usage is implied rather than stated: the clipboard note hints this is for text entry where clipboard usage is undesirable, and 'focused application' implies a focus precondition. There is no explicit when-to-use vs 'key' (single keystrokes, shortcuts, non-ASCII keys) and no statement of when to prefer the clipboard approach instead.

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