Send Key Event

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

Annotations already indicate non-read-only, non-destructive, and open-world behavior. The description adds 'safe' and limits allowed keys, but does not disclose behavior for invalid keys or permissions, or further context beyond annotations.

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 short sentences, no redundant info, and front-loads the key action. Each part 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 tool with one parameter and no output schema, the description is sufficient. It explains what keys are safe to send. Could mention that it is for Android ADB, but the tool name implies it.

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 covers the parameter key with 100% description coverage (examples). The description adds explicit allowed categories (navigation, editing, media, alphanumeric) which goes beyond the schema's examples, providing extra semantic meaning.

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 verb 'Send' and the resource 'key event' with concrete examples (HOME, BACK, ENTER) and allowed categories. It distinguishes from sibling tap/text tools but does not explicitly differentiate from them.

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 implies when to use (sending key events) and lists allowed keys, but does not provide when-not-to-use or alternative sibling tools like adb_tap or adb_text.

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