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

Annotations signal a write operation (readOnlyHint=false) and non-destructive behavior, and the description adds substantial behavioral detail beyond those hints: idempotency keyed on acpIntentId with replay=true, the shape/enum of finalization.status, and an auth note that the tool never executes without a valid X-MCP-API-Key. The scoped idempotency claim refines rather than flatly contradicts the general idempotentHint=false.

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 core purpose is front-loaded, and the status list and auth note are set off in compact blocks. It is longer than minimal because the tool is complex, but almost every sentence adds information and it does not repeat the schema.

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 mutating, authenticated tool with no output schema and five parameters, the description covers a lot: sequencing, statuses, idempotency, auth, and return envelope. However, it omits any explanation of agentBearer and consumerAgentKind and does not describe failure behavior beyond the generic status enum, so an agent cannot fully reason about all inputs.

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 0%, so the description must carry parameter meaning. It clarifies acpIntentId (Stripe payment intent) and holdId (optional inventory hold), but leaves agentBearer and consumerAgentKind completely unexplained, and orderId only by inference from 'droplinked order.' With five parameters and zero schema coverage, this is only partial compensation.

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 opens with a specific verb and resource: 'Finalize a droplinked order using a Stripe ACP payment intent and an optional inventory hold.' It also places the tool in the pipeline (after find_inventory + quote_inventory_available + create_payment_intent) and names the return statuses, so an agent can distinguish it from cart, quote, and verification 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?

It gives an explicit call sequence: 'The consumer agent calls this after find_inventory + quote_inventory_available + Stripe ACP create_payment_intent' and says it 'Closes the agent-to-agent transaction loop.' It does not spell out when not to use alternatives, but the pipeline context is clear enough.

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