add_device_instance

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false. The description adds the auth requirement ('requires write permission') and the usage context, which go beyond annotations. It does not discuss failure modes or side effects, but the annotations cover the safety profile sufficiently.

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 with no redundancy. The core purpose is front-loaded, followed by a usage qualifier. Efficient and directly informative.

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 create operation with no output schema, the description covers the essential purpose and usage context. It lacks an explicit note about return values (e.g., whether the created instance ID is returned), but given the high schema coverage and annotations, this is a minor gap. The description is adequate for an agent to invoke the tool correctly.

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 all parameters already have detailed descriptions, including examples for wild_value. The tool description does not add extra semantic value beyond what the schema provides, so the baseline of 3 applies.

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 verb 'Add' and the resource 'monitored instance to a datasource on a device', making the purpose unambiguous. It also distinguishes from sibling update/delete instance tools by focusing on creation and mentions a specific use case (datasources without Active Discovery).

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?

It provides a clear condition for use ('Used for datasources without Active Discovery') and an example (ServiceStatus), giving the agent a decision rule. It doesn't explicitly list alternatives or exclusion cases, but the context strongly implies when to choose this tool over related instance operations.

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