Rename device

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

Annotations already declare destructiveHint=true, readOnlyHint=false, idempotentHint=true, and openWorldHint=true, so the safety profile is structured. However, the description adds zero behavioral context beyond that — it does not mention that the rename overwrites the existing name, any side effects, or authorization needs. With the annotation burden already covering the basics, a 2 reflects that the description contributes no extra transparency.

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 terse sentences with zero filler. The core action is front-loaded and the only added guidance ('Preferred: idx') is placed immediately, making the description maximally efficient.

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?

Given that an output schema exists, all three parameters are documented in the schema, and annotations carry the destructive/mutation/idempotent profile, the description is largely adequate. A fully destructive tool could arguably use one sentence flagging that renaming overwrites the current name, but with the structured fields already covering safety, the short description is sufficient.

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 documents idx, new_name, and old_name fully. The description's 'Preferred: idx' guidance does add a minor prioritization signal, but the schema itself already states idx is 'preferred over name when known', so this largely duplicates existing schema information. Baseline 3 is appropriate since the schema carries the load and the description adds little beyond it.

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 states a specific verb ('Rename') and resource ('device'), making the core purpose unambiguous. It is clearly distinct from siblings like delete_device, create_virtual_sensor, and toggle_switch, though it does not explicitly call out its relationship to update_device_value, which also modifies a device. The purpose is clear but sibling differentiation is left implicit.

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?

No guidance is given on when to use this tool versus alternatives, and no exclusions are stated. The only hint, 'Preferred: idx', is parameter-selection guidance rather than usage context. An agent is given no indication of when renaming is appropriate compared to, say, update_device_value or delete_device.

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