Press a remote key

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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), so the bar is lower. The description adds only that repeat produces repeated presses, without disclosing what receives the key (focused app vs. system), latency/blocking behavior, or any prerequisite state such as the device being powered on.

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?

A single sentence that puts the verb and target first, then supplies the example. There is no filler and nothing redundant with the schema.

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 two-parameter input tool with an output schema (so return values need no explanation) and full annotation coverage, the description supplies the essential purpose plus one grounded example. It stops just short of stating when this tool should be preferred over higher-level siblings or whether the target must be focused/awake.

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 only 50% (the 'key' enum has no description) and 'repeat' is minimally documented ('How many times to press the key (1-10).'). The description compensates by tying repeat to an observable effect ('repeat=3 to move down three rows') and by framing the key values as Shield remote-control keys, which is genuine meaning beyond the schema.

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 ('Press') and resource ('a remote-control key on the Shield'), making it immediately distinguishable from siblings like launch_app, set_power, and get_status. An agent can tell this is the low-level input-injection tool without opening the 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?

Usage is implied by the concrete example (DPAD_DOWN with repeat=3 to move down three rows), which shows the intended navigation scenario, but the description names no alternatives and gives no explicit when-to-use/when-not-to-use guidance. It is adequate but leaves routing to inference.

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