Digital Inputs

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds value by specifying that it reads state and alarm data, and notes the constant Unit ID. It also implicitly indicates support for both Modbus and MQTT transports via the parameter 'transport', which aligns with the annotations. No contradictions.

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?

Two sentences, no unnecessary words. The first sentence states the core purpose, and the second adds specifics. Every sentence earns its place, making it highly efficient and easy to parse.

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?

Given the presence of an output schema (not shown but indicated), the description does not need to detail return values. It covers the core behavior, device-specific behavior (Cerbo GX primary input), and included data. Slight lack of error or limitation context, but sufficient for a read-only tool with rich structured metadata.

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 the parameters are well-documented in the schema itself. The description adds minimal new parameter insight: it mentions 'Unit ID is always 100' (not a parameter) and lists the returned data fields. This provides some context but does not significantly enhance parameter understanding beyond the schema.

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 uses a specific verb 'Read' and identifies the resource 'digital input data from the GX device.' It further lists the data included (state, type, alarm, pulse count), making the purpose unambiguous and distinguishing it clearly from sibling tools like victron_battery_status or victron_charger_status.

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 implies usage context by noting the device (Cerbo GX, primary digital input) and a constant (Unit ID is always 100). While it does not explicitly state when not to use or offer alternatives, the sibling list naturally differentiates, and the description is clear enough for the intended usage.

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