get_device_data

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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds meaningful behavioral context: the default time-window behavior and the correct ID source. These go beyond the schema and annotations Encapsulate. It does not cover return format or pagination, but the added context is valuable.

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?

Very concise: a one-line purpose followed by a compact 'Common mistakes' section. Every sentence earns its place, and the key warnings are front-loaded. No fluff, and the structure makes the pitfalls easy to scan.

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 6-param read-only tool with full schema coverage retriever, the description provides the essential prerequisite (ID source) and a critical behavioral caveat (time window). It does not explain the return data structure or instance_id semantics, but those are partially covered by schema parameter descriptions. Overall, sufficient for correct invocation.

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 covers 100% of parameters, so baseline is 3. The description adds semantics by clarifying that device_datasource_id is the device-specific ID (from get_device_datasources) rather than the global datasource definition ID, and by explaining that start_time/end_time control the time window. This goes beyond the schema descriptions.

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?

States a specific verb and resource: 'Get metric data for a device/resource datasource instance.' It identifies the tool's purpose as retrieving metric data for a datasource instance, and the common-mistakes note about device_datasource_id helps distinguish it from get_device_datasources. However, 'device/resource' is slightly ambiguous and it does not explicitly name an alternative for comparison.

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?

Provides clear usage context by specifying a prerequisite (get device_datasource_id from get_device_datasources) and a common pitfall (returns most recent data unless start/end specified). This is actionable for an agent. It does not mention alternatives for retrieving metric data, but the prerequisites and default behavior are sufficient to guide invocation.

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