write_digital

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

With no annotations, the description carries full burden and does well: it discloses the non-obvious read-back behavior ('read back from hardware, not echoed') and explains why it returns the state. The environment-variable requirement is another important behavioral context. This goes beyond the schema and gives the agent confidence about side effects and verification.

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 two sentences. The first is the core action; the second adds a crucial behavioral note. No wasted words, and the most important information is front-loaded.

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 with only two parameters and an output schema. The description explains the action, the prerequisite, and the return value semantics. It doesn't detail channel syntax, but given the simplicity and the presence of an output schema, the description is sufficiently complete for most agents.

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 0% and no parameter descriptions exist. The description implicitly maps value to 'high or low' (true/false) but does not explain the channel parameter format or possible values. This is partial compensation; the value semantics are clear, but channel remains ambiguous.

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 opens with a specific verb+resource: 'Set a digital output line high or low.' This clearly distinguishes the tool from siblings like read_digital (read vs. write) and write_analog (digital vs. analog). The purpose is unequivocal.

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 provides a key usage condition: 'Requires DAQ_MCP_ALLOW_WRITE=1.' This tells the agent when the tool can be used (when write access is enabled). It doesn't explicitly list alternatives, but the context of setting a digital output is clear enough for a simple write operation.

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