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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, so the description doesn't need to restate those. It adds useful context beyond annotations: the rename only affects the account-visible label, and access roots, command guardrails, and resource limits stay on the computer itself. This clarifies the scope of the operation and what is not changed, which is valuable behavioral context.

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?

Three sentences, each earning its place: the first states the purpose and scope, the second routes away from a confusingly similar sibling, the third clarifies what is not affected. The key information is front-loaded and there is zero 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?

For a simple 3-parameter tool with full schema coverage, an output schema, and annotations covering safety/idempotency, the description is nearly complete. It could arguably mention that the device must come from list_devices, but the schema already says that. The only minor gap is that it doesn't describe the return value, but the output schema exists, so the description needn't explain that.

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 three parameters. The description adds the semantic context that 'value' is the new label and 'config_key' is supported as 'device_name', but it doesn't go beyond the schema's own descriptions. Baseline 3 is appropriate when the schema carries the parameter documentation burden.

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 ('change'), a specific resource ('account-visible label of one paired computer'), and explicitly distinguishes it from the sibling set_config_value. This clearly differentiates it from the many sibling tools and leaves no ambiguity about what the tool does.

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 explicitly says when to use it ('when the user wants to change the account-visible label of one paired computer') and explicitly says when not to use it ('Do not use set_config_value for renaming'), naming the alternative and its different purpose. This is exactly the kind of routing guidance an agent needs.

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