Sets EtherCAT slave RxPDO outputs, such as digital outputs and motor target position or controlword, by writing cyclic output process data for the specified slave index.
Write cyclic output process data (RxPDO outputs: Digital Outputs, motor target position/controlword).
| Name | Required | Description | Default |
|---|---|---|---|
| values | Yes | Key-value map of process data outputs to set | |
| slaveIndex | Yes | Slave index on the bus |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden and largely fails it. It does not state that writing RxPDO values immediately affects live device/motor behavior, whether values persist or are one-shot cyclic writes, what happens on an invalid key or non-operational slave, or any failure semantics for an industrial control mutation.
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 filler; the core action and resource come first and the examples follow compactly.
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 live-hardware mutation with nested untyped parameters, no annotations, and no output schema, the description is thin: it omits preconditions, safety implications, error behavior, and key naming for the values map. An agent could formulate the call but not predict its effects or failure modes.
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 baseline would be 3, but the description adds real meaning for the untyped `values` object (additionalProperties: {}) by naming the kinds of outputs it expects: digital outputs and motor target position/controlword. It does not explain how keys are formed (name vs index), which is the remaining gap.
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 ("Write") plus a specific resource ("cyclic output process data / RxPDO outputs"), with parenthetical examples of what that data covers (Digital Outputs, motor target position/controlword). This differentiates it from write_sdo and read_pdo by direction and data type, though no sibling is named explicitly.
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 guidance on when to use this versus write_sdo or drive_control, and no stated preconditions (e.g., slave must be in Operational ESM state for RxPDO writes). The agent must infer the context entirely from the tool name and domain knowledge.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.