plaid-mcp

update_external_debt_tool

Modify specific fields of an existing external debt record, such as APR, balance, or due date, to keep payoff tracking accurate. Requires Plaid.

Instructions

Update any subset of fields on an existing external debt.

Plaid-only.

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": {
      "debt_id": "<debt_id>"
    },
    "name": "update_external_debt_tool"
  }
}

Input Schema

Name	Required	Description	Default
`apr`	No
`name`	No
`note`	No
`balance`	No
`debt_id`	Yes
`promo_expires`	No
`minimum_payment`	No
`next_payment_due_date`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 11, 2026

TDQS

A3.5/5.0

Behavior3/5

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

With no annotations, the description carries the full burden. It does disclose that only a subset of fields is updated and that the debt already exists, which is useful. But it does not explain what happens when a field is omitted versus set to null, whether changes are reversible, or what occurs if the debt_id does not match an existing debt.

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

Conciseness5/5

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

The description is extremely concise and front-loaded. The first sentence states the action and scope, and the second adds a relevant constraint. There is no filler or redundant restating of the tool name.

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?

For a mutation tool with eight parameters, no annotations, and no output schema, the description is too sparse. It does not explain required parameters, null-vs-omit semantics, return values, or error behavior, leaving significant gaps for an agent trying to invoke the tool correctly.

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

Parameters2/5

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

Schema description coverage is 0% and the description does not compensate. It does not mention debt_id as the required identifier or clarify that null values likely mean 'clear the field' rather than 'leave unchanged.' With eight parameters and no descriptions, an agent is left to infer the meaning and update semantics from names and types alone.

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 clearly identifies the operation as updating an existing external debt and emphasizes partial updates ('any subset of fields'), which distinguishes it from sibling tools like add_external_debt_tool, remove_external_debt_tool, and list_external_debts_tool. The resource and action are both specific and unambiguous.

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

Usage Guidelines3/5

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

The description implies usage: update an existing external debt, and the 'Plaid-only' note provides a useful eligibility constraint. However, it does not explicitly say when not to use it or mention alternatives such as add_external_debt_tool for creating debts or remove_external_debt_tool for deleting them.

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