Lists datasources applied to a device, returning the device_datasource_id values needed to fetch device data.
Get datasources applied to a device (resource)
Common mistakes: Returns device-datasource associations not definitions. The ID returned here is device_datasource_id for use with get_device_data.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Max results | |
| device_id | Yes | Device ID |
Changes observed during successful MCP inspections.
v4.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral nuance beyond annotations: it warns that the result contains associations, not definitions, and that the returned ID should be used with get_device_data. This corrects a likely misinterpretation.
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 concise sentences. The main purpose is front-loaded, and the high-value clarification about associations versus definitions is delivered immediately without any 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 simple read-only listing tool with complete schema annotations, the description covers the critical context: what is returned (associations, not definitions) and how the returned identifier should be used downstream. It does not detail response fields, pagination, or ordering, but these are less critical given the annotations and simple parameter set.
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?
The input schema covers both parameters with descriptions (100% coverage), so the schema carries the parameter semantics. The description does not add parameter-level detail but does clarify the meaning of a returned ID, which indirectly relates to how the response should be used. This falls at the baseline for fully documented schemas.
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 states the operation: 'Get datasources applied to a device (resource)'. It goes further by explicitly distinguishing the result from definitions ('Returns device-datasource associations not definitions'), which sets it apart from siblings like get_datasources and get_datasource.
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 clarifies what this tool returns versus definitions, implicitly steering agents toward get_datasources for definitions. It also gives downstream guidance that the returned ID is a device_datasource_id for use with get_device_data. However, it does not explicitly name sibling tools or state exact conditions for choosing alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.