adb_key

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

No annotations are provided, so the description carries the burden. It indicates this is an input injection action (pressing keys), which implies it sends events to the device. It doesn't disclose whether key injection requires specific authorization, whether certain keys fail on unrooted devices, or whether the injection targets the foreground app only. Minimal but not misleading.

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?

Single sentence, front-loaded with the action and key examples. Every element earns its place. Slightly dense with the long key list, but the list itself is informative and useful.

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 two-parameter tool with no output schema, the description is reasonably complete. It covers what keys are accepted and both input formats. It's missing guidance on serial semantics (present in schema) and edge cases like invalid keys, but given the simplicity this is acceptable.

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 50% (serial is described, key is not). The description partially compensates by listing valid key names and noting numeric keycodes are accepted, which adds syntax detail beyond the bare 'key: string' schema. However, it doesn't clarify the numeric keycode range or format.

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?

Specific verb+resource+mechanism: 'Press a remote/D-pad key by name... or numeric keycode'. Clearly distinguishes from siblings like adb_tap (screen coordinate) and adb_text (text input). Lists concrete key examples that disambiguate the input style.

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 explains what keys can be pressed and that both names and numeric keycodes are accepted, which implies usage context. However, it doesn't state when to prefer this over adb_tap or adb_shell for input, nor any exclusions. The serial 'omit if only one device' guidance is in the schema, not the description.

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