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

Annotations already declare idempotentHint true and destructiveHint false, yet the description adds real substance: nothing is charged, the result is a pending item awaiting admin action, and a duplicate request for the same tier returns the existing open request. The only gap is what the returned request object looks like, which is minor for a mutation tool with no output schema.

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?

Four short sentences, front-loaded with the action and the no-charge guarantee before the tier and duplicate-handling rules. The business/Plus mapping is stated twice across description and schema, a small redundancy in an otherwise tight definition.

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 one-parameter mutation tool with annotations covering the safety profile, the description covers cost, approval flow, idempotency, and conflict handling. It does not describe the shape of the returned request or what happens to the existing plan while the request is pending, which an agent would still need to learn from the call itself.

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% and the single enum value's meaning ("business is the Plus plan") is already documented in the schema, so the description largely repeats it. The one added nuance is that the enum values are the only accepted tiers, which the agent can already read from 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?

The first sentence gives a specific verb and resource plus the target state: "Asks an account admin to move this seat to Pro or Plus." It makes clear this is the requester side of the workflow, distinguishing it implicitly from approve/decline/cancel siblings, though it never names an alternative tool outright.

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?

It states the situation (moving a seat up a tier), clarifies no charge occurs and that an admin decides, and gives the prerequisite rule: a different tier requires cancelling the open request first. It stops short of naming cancel_membership_request explicitly, leaving the agent to match that instruction to the sibling.

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