press_key

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

Annotations already indicate readOnlyHint=false, so the agent knows it's a mutating operation. The description adds the term 'safe' and the scope of supported keys, which is useful but doesn't disclose side effects (e.g., POWER may sleep/wake device). No contradiction with annotations, but limited extra behavioral context.

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 a single, focused sentence front-loaded with the core purpose. Every word earns its place, with no filler or redundancy.

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?

The tool is simple, but with multiple sibling input methods (press_key_sequence, tap, swipe, type_text), the description lacks an explicit pointer to alternatives. No output schema, but the lack of return-value info is acceptable for a fire-and-forget key press. Slightly incomplete for disambiguation.

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 100%, so parameters are already well-documented. The description adds no additional parameter semantics beyond what the schema provides. Baseline 3 applies.

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 identifies the action ('Send') and the resource ('Android key event'), with specific scope ('named', 'D-pad and Fire TV remote navigation keys'). It distinguishes from touch-based siblings like tap/swipe, but does not explicitly differentiate from the closely related press_key_sequence, so it's clear but not fully differentiated.

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?

No explicit guidance on when to use this tool vs alternatives. It implies use for named key events but doesn't mention press_key_sequence for multiple keys or type_text for text input. No exclusions or alternative recommendations are provided.

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