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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context by disclosing the dry_run -> notified -> (kept | applied | superseded) lifecycle and the per-period nature of the results. No contradictions with annotations.

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 tight and front-loaded, with an effective one-line purpose followed by useful lifecycle and API context. The 'Mirrors GET /api/v1/rightsize-recommendations' sentence is slightly redundant but still informative and not fluff.

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?

With a rich input schema, output schema, and strong read-only/idempotent annotations, the description provides enough behavioral framing: what is listed, the lifecycle, the filtering period, and the role of the tool. It does not explain optional filter defaults, but those are already visible in the schema.

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 only 17%, so the description carries extra responsibility. It adds 'per-period' meaning for the from/to filters and the lifecycle states align with status, but it does not explain the action enum, limit pagination, or business_id semantics beyond the minimal 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?

The description names a specific action and resource ('List ... auto-right-size decisions'), ties it to a concrete state lifecycle, and states the human-facing question it answers. It is clearly distinct from generic list_plans or list_subscription_history siblings.

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 establishes clear intended use by asking 'is this business right about to be right-sized' and explicitly names the mirroring API endpoint. It does not enumerate exclusions or compare against sibling list tools, but the use case is unambiguous.

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