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

Annotations give destructiveHint=true; the description adds genuinely non-obvious behavior beyond that: dependent services go offline and the instance keeps being billed while stopped, plus the underlying PUT endpoint. Auth/permission requirements and reversibility nuance are not covered, so not a 5.

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 short sentences, front-loaded with the action, then consequence, then API mapping. Every sentence earns its place with 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?

For a two-parameter mutation with no output schema and only a destructiveHint annotation, the description supplies the missing behavioral context (downtime, continued billing). It is complete enough to call correctly; only permission or confirmation requirements are unaddressed.

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 coverage is 100%, so both parameters (instance_id and region) are already fully documented in the schema, including the region default and the civo_list_regions pointer. The description adds nothing about parameters, so baseline 3 is correct.

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 ('Power off one instance') and explicitly names the counterpart operation civo_start_instance, letting an agent distinguish it from sibling tools like civo_reboot_instance and civo_start_instance without opening a schema.

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 frames the operational context: anything the instance serves goes offline and it must be started again. The inverse tool is named, which implicitly routes the agent. It stops short of explicitly contrasting with civo_reboot_instance (which also takes an instance down), so not a full 5.

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