purchase_commerce_servicePurchase a dynamically admitted service with an owned wallet through the existing direct-payment and ledger authority. Exact replay returns the same purchase and payment.
| Name | Required | Description | Default |
|---|---|---|---|
| input | Yes | A JSON object accepted only when its canonical serialized form is at most 50000 characters and its nesting depth is at most 64. | |
| serviceId | Yes | ||
| buyerWalletId | Yes | ||
| idempotencyKey | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate this is not read-only and not destructive, so the description carries a limited burden. It adds useful behavioral context by stating that 'Exact replay returns the same purchase and payment,' which signals idempotency, and by naming the authority path for the mutating purchase. There is no contradiction with the 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 two sentences with no filler. The primary purpose is front-loaded, and the idempotency guarantee is placed second without repeating schema or annotation information. Every sentence adds value.
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 required four-parameter financial mutation with no output schema, the description gives a solid high-level picture but omits important operational context: what 'input' should contain, how the response is structured, how to obtain or identity a 'dynamically admitted service,' and when to prefer this over nearby commerce tools. These gaps make the definition adequate but not complete.
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 low: only 'input' has a real description, and even that is mostly constraint-based. The description compensates partially by semantically mapping 'service' to serviceId, 'owned wallet' to buyerWalletId, and 'exact replay' to idempotencyKey. The 'input' parameter remains semantically unexplained beyond size and depth limits, which prevents a higher score.
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 action and resource: 'Purchase a dynamically admitted service with an owned wallet.' It adds meaningful context about funding and authority and highlights replay semantics. However, it does not explicitly differentiate this tool from commerce siblings like execute_authorized_purchase or recover_commerce_purchase, so it stops short of full clarity.
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?
Usage is implied by the description: the service must be 'dynamically admitted,' the wallet must be 'owned,' and payment must flow through 'existing direct-payment and ledger authority.' Yet there is no explicit statement of when to use this tool versus alternatives, nor any mention of exclusions or prerequisites beyond those hints.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
The set has multiple near-synonymous read and recovery surfaces, e.g. get_commerce_purchase_status vs get_purchase_recovery_status vs recover_authorized_purchase vs recover_commerce_purchase, and discover_assurance_services vs discover_commerce_index vs get_discovery_manifest vs search_verified_offers. Long descriptions are required to tell them apart, so misselection is likely.
All names follow a readable snake_case verb_noun pattern, with get_, request_, create_, verify_, and recover_ prefixes used consistently. The main deviation is read operations split across get_/discover_/inspect_/search_/list_, which is still understandable but not perfectly uniform.
At 50 tools this is in the extreme-mismatch band for an MCP server. Even with a broad payment/commerce/discovery domain, dozens of get/status/recovery tools could be consolidated or parameterized.
The toolset covers the major lifecycles: registration, wallet, funding, payment, commerce offer/purchase/fulfillment/refund, mandates, and verification. Minor gaps such as no service unregister/update, no payment-request cancellation, and no wallet deletion are workable but not fatal.