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

With no annotations, the description carries the full transparency burden. It discloses that execution is synchronous ('the call returns once farmd acks'), defines the coordinate system (fractions 0..1), and enumerates the available ops with their effects. It stops short of describing error handling or rate limits, but the core behavior is well covered.

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 compact and front-loaded with the core purpose, followed by the critical distinction from phone_command and coordinate rules. The ops are presented as a readable bullet list. Every sentence contributes; there is no filler.

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 tool with 11 parameters, no output schema, and no annotations, the description covers the essential operational knowledge: the required slot state, the op types, coordinate semantics, and synchronous execution. It does not specify the return value format or error scenarios, but for a raw-input tool these are secondary and partly implied by the ack statement.

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 100%, so the baseline is 3, but the description adds real semantic value beyond the parameter descriptions: it explains that coordinates are fractions of screen dimensions (0 = left/top, 1 = right/bottom), clarifies each op's parameter mapping (e.g., swipe start/end points, steps controlling gesture speed), and gives the default for steps. This helps the agent construct correct parameter combinations.

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 and resource ('Send a raw input primitive to a farm phone') and explicitly distinguishes itself from sibling phone_command by contrasting queue-based shortcuts with direct farmd socket ops. An agent can immediately understand what this tool does and how it differs from its closest alternative.

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?

It explicitly says 'Unlike phone_command (which queues an on-phone Shortcut), these are direct farmd socket ops and run synchronously', giving a clear when-to-use-this-vs-that. It also states a precondition ('The slot must be cast/live') that an agent must check before calling.

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