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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=true, so the bar is lower. The description adds genuinely non-derivable context: the cluster 'will begin provisioning immediately after creation' (an asynchronous side effect that starts even if the agent stops watching) and which credentials must exist first. It does not address cost, reversibility, or cleanup, which is the remaining gap.

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 and provider, then prerequisites, then the immediate-provisioning caveat, then helper-tool pointers. No filler and nothing buried.

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 13-parameter, non-idempotent creation tool with no output schema, the description covers what it creates, what it needs, and that provisioning starts asynchronously, which is enough to invoke it correctly. It is slightly thin on what the call returns (cluster ID/handle for later polling) and on failure or rollback behaviour.

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 itself carries rich detail (region naming rules, distribution enum, availability-zone quorum caveat, version tagging rules). The description only repeats the credential and flavor parameters at a high level, adding no syntax or default information beyond the schema, 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+resource+provider: 'Create and provision a new Kubernetes cluster on OVH Cloud.' It is trivially distinguishable from siblings like create_aws_cluster, create_hetzner_cluster, and create_proxmox_cluster, so an agent can pick the right provider tool 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?

Gives clear entry conditions (an OVH API credential, an SSH key credential, a region) and explicitly routes the agent to list_provider_credentials for credential IDs and list_instance_types for flavor sizes. It stops short of stating when NOT to use this tool (e.g. versus create_managed_cluster or import_cluster), so it is clear context without exclusions.

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