grubhub-mcp

add_campus_card_payment

Attach a linked campus card to a cart to pay the remaining balance. Optionally specify the amount in cents.

Instructions

attach the linked campus card, such as CarolinaCard, to a cart.

Args: cart_id: The cart ID payment_id: Campus-card payment ID; default is campus_card amount_cents: Optional amount in cents; omit to cover remaining balance

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "cart_id": "<cart_id>"
    },
    "name": "add_campus_card_payment"
  }
}

Input Schema

Name	Required	Default
`cart_id`	Yes
`payment_id`	No	campus_card
`amount_cents`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jun 18, 2026

TDQS

B3.3/5.0

Behavior2/5

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

No annotations are provided, so the description must carry the full burden. It does not disclose side effects (e.g., what happens if the card is not linked, whether existing payment is replaced), permissions required, or output format. The existence of an output schema is not addressed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is brief and organized with a header line and an Args block. Every sentence serves a purpose. Slight improvement could be removing the 'Args:' label since parameters are obvious, but it's not detrimental.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite having an output schema, the description does not mention what the tool returns. There is no discussion of prerequisites (e.g., need for a linked campus card) or error conditions. For a 3-parameter mutation tool, this is insufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 0% schema coverage, the description adds crucial meaning: it explains 'cart_id' is the cart ID, 'payment_id' is the campus-card ID with default 'campus_card', and 'amount_cents' is optional with the note 'omit to cover remaining balance'. This substantially clarifies usage beyond the raw schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description explicitly states 'attach the linked campus card to a cart', with a specific example 'CarolinaCard'. This clearly distinguishes it from sibling 'add_payment_to_cart', which is generic. The verb 'attach' combined with the resource 'campus card' gives precise purpose.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives like 'add_payment_to_cart'. The description lacks explicit conditions, prerequisites, or exclusion scenarios. The agent has no help deciding between campus card and other payment methods.

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