add_devices_to_group

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

With no annotations provided, the description carries the full burden and exceeds expectations. It discloses that the operation is additive and idempotent, merges rather than replaces, avoids duplicates, and treats empty/None as a no-op. This gives the agent a thorough understanding of the tool's behavior.

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 well-structured with a clear summary line followed by focused paragraphs. Every sentence provides essential information—purpose, parameter guidance, and behavioral details—without repetition or fluff. It is concise yet complete.

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 two-parameter tool with an output schema, the description is fully sufficient. It covers how to find valid group names, explains the exact effect on existing group contents, and addresses edge cases like empty input. No critical gaps remain.

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?

Although the schema already covers both parameters, the description adds significant meaning: 'name' must be valid and can be looked up via get_device_groups; 'devices' is described with merge semantics, idempotency, and no-op behavior for empty lists. This goes well beyond the schema's brief 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?

The description clearly states the verb ('Add') and the resource ('one or more devices to a device group'). It distinguishes itself from siblings like remove_devices_from_group and create_device_group by specifying the additive, targeted action. The first sentence is a precise summary.

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 provides context by noting that the group name must be valid and explicitly points to get_device_groups for finding available groups. It does not explicitly contrast with remove_devices_from_group or create_device_group, but the additive/idempotent wording makes the intended use case clear.

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