Send Android key

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

Annotations already declare readOnly=false, destructive=false, idempotent=false and openWorld=false, so the safety profile is carried by structured data. The description adds one real behavioral trait, that press options are 'capability-gated' (they may be unavailable depending on device capability), but it is too vague to be actionable and says nothing about how keys are resolved or what failure looks like.

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 front-loaded sentence with no padding or repetition. It is efficient, though the vague 'capability-gated' clause consumes words without delivering usable detail.

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 6-parameter, non-idempotent input tool with low schema coverage, the description leaves key syntax, action semantics, and duration behavior undocumented. An output schema exists so return values need not be covered, but the invocation-relevant gaps remain substantial.

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 description coverage is only 33% (only serial and displayId are documented), so the description must compensate for key, action, source, and durationMs. It touches them only obliquely ('symbolic or numeric' hints at key format, 'gamepad source' echoes the source default, 'press options' hints at action) without explaining the accepted key syntax, the meaning of durationMs, or the non-idempotent semantics.

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 gives a specific verb and resource ('Send symbolic or numeric Android keys'), so an agent knows this injects key events rather than taps, swipes, or text. However, it never names the sibling it differs from (mobile_input_text, mobile_input_key_combination, mobile_input_key_sequence), so sibling differentiation is only implied by the 'key' noun.

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?

There is no when-to-use guidance and no mention of when to prefer this over mobile_input_text or the combination/sequence variants. The phrase 'capability-gated press options' gestures at a precondition but does not state one.

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