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

Annotations already signal that this is a mutating, non-idempotent, non-destructive operation. The description adds 'named, reusable' but does not disclose additional behavioral details such as duplicate-name handling or what happens on invalid device_ids. It is consistent with annotations and minimally adequate.

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 a single, focused sentence with no filler. Key qualifiers ('named, reusable') are front-loaded, and every word contributes to understanding the tool's purpose.

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?

The tool has low complexity, a fully documented schema, and annotations covering the safety profile. The description is sufficient for basic invocation, though it does not mention return values or duplicate-name behavior; these are minor gaps for a create 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%, with both parameters already documented: name is a human-readable string, and device_ids must come from list_preview_devices with invalid ids rejected. The description adds little beyond the schema, so the baseline of 3 is appropriate.

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 ('Create') and resource ('preview device set'), and adds clarifying qualifiers 'named, reusable'. This distinguishes it from siblings like create_preview_run, replace_preview_device_set, and archive_preview_device_set.

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 when to use the tool—when creating a named, reusable set of preview devices—but gives no explicit guidance about alternatives such as replace_preview_device_set for updates or archive_preview_device_set for removal. Usage context is present but not elaborated.

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