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

No annotations are provided, so the description carries the full behavioral burden. '获取' implies a read-only query and the scope rule per mode is stated, but it says nothing about permissions, rate limits, ordering, or pagination behavior, and return values are covered by the output schema.

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?

A single sentence, front-loaded with the primary action and scope, followed by a parenthetical domain definition. The parenthetical is slightly long but earns its place by disambiguating the resource; no 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?

With an output schema present, return values need no explanation, and all three optional parameters are documented. The definition covers scope and the domain concept adequately; only behavioral notes like permissions or ordering are absent, which is a minor gap for a simple read tool.

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 limit, cursor, and roomId semantics are already documented in the schema, including the 'no roomId means all groups' rule. The description restates that same roomId behavior without adding format or syntax detail, so baseline 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?

States a specific verb and resource ('获取...设备组') and adds a definition of what a device group is (same device type grouped, e.g. light group, switch group), which helps separate it from the sibling get_devices. It does not explicitly name or contrast a sibling tool, so it stops short of a 5.

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?

Clearly lays out the two usage modes: omit the room filter to get all groups under the user's home/project, or scope to a single room. That is clear context for choosing a mode, but it names no exclusions and no alternative tools (e.g. get_devices) the agent should prefer in other cases.

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