update_device_group

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

Annotations already indicate this is a mutating, non-idempotent operation. The description adds the write-permission requirement, which is useful authentication context, and clarifies that custom properties are merged rather than replaced. No contradiction with annotations exists.

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 short sentences with no filler. It front-loads the action and resource, then adds the two most decision-relevant details: permission requirement and merge behavior.

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 mutation tool with 7 well-described parameters, the description provides the essential extra context: permission requirement and merge semantics. There is no output schema, so return-value expectations are not covered, but this is a minor gap for an update operation.

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 schema already documents all 7 parameters clearly. The description adds minimal parameter-level value beyond reinforcing the custom-properties merge behavior already stated in 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 clearly states a specific action ('Update') and a specific resource ('device/resource group'), making the tool's purpose immediately identifiable. It does not explicitly name sibling tools like update_collector_group or update_recipient_group, so some differentiation is left to inference.

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 the tool should be used when updating an existing device group and provides a prerequisite ('requires write permission'). It does not explicitly describe when to prefer this over create/delete or other update-group siblings, leaving usage context mostly implicit.

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