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

Annotations already declare destructiveHint=true, readOnlyHint=false and non-idempotency, so the risk profile is partly structured. The description adds real context beyond that: restarting interrupts the service and can disrupt active users, plus a recovery-expectations caveat. It stops short of saying whether dependent services or sessions are affected or what happens to an unknown service name.

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 sentences, front-loaded with the action and constraint, followed by the impact warning. Nothing is redundant or padded.

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?

An output schema exists, so return values need not be explained, and annotations plus the interruption warning adequately cover risk for a destructive operation. A minor gap remains around failure modes (service not found, permissions) and whether restart implies a stop-then-start ordering.

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%, and the schema already explains the device id, the service/unit/launchd label, and the user-vs-system scope choice with a default recommendation. The description only restates that exactly one named service and a paired computer are involved, adding no syntax or format detail beyond the schema.

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 ('restart'), a narrowly scoped resource ('one specifically named OS service'), and the target environment ('paired computer'). The verb alone distinguishes it from the sibling lifecycle tools service_start, service_stop, service_status, and service_list.

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?

Gives a conditional trigger ('when requested') and a pre-flight check ('check scope and recovery expectations first'), which implies appropriate usage. However, it never names the adjacent alternatives (service_stop/service_start, or power_restart for the whole machine) or states when not to use this tool, leaving routing to inference.

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