open-banking-io MCP Server

list_accounts

List bank accounts with balances, IBAN, owner, and bank name. Sensitive data is decrypted in-process from zero-knowledge envelopes.

Instructions

List the user's bank accounts with balances, IBAN, owner and bank name.

Sensitive fields are decrypted in-process from the zero-knowledge envelopes. Use an account's id for get_balances / get_transactions.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_accounts"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 20, 2026

TDQS

A4.5/5.0

Behavior4/5

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

No annotations are provided, so the description must carry the behavioral disclosure burden. It does so by revealing that 'Sensitive fields are decrypted in-process from the zero-knowledge envelopes,' which is non-obvious and important context for the agent. It does not mention every possible behavioral trait, but it covers the most relevant security-sensitive aspect.

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 three concise sentences: the first states the purpose and returned fields, the second provides essential security context, and the third gives actionable downstream usage. Every sentence earns its place with no redundancy.

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

Completeness5/5

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

Given the tool has no parameters, an output schema is present, and the description covers purpose, fields, security behavior, and how to use the result with sibling tools, it is complete enough for an agent to select and invoke it correctly. No significant gaps remain.

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?

The input schema is empty with zero parameters, so the description does not need to explain parameter semantics. Per the zero-parameter baseline, a score of 4 is appropriate since there is nothing ambiguous to clarify.

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 starts with a specific verb and resource: 'List the user's bank accounts with balances, IBAN, owner and bank name.' It clearly defines the tool's scope and differentiates it from siblings by noting that account IDs should be used with get_balances/get_transactions.

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

Usage Guidelines4/5

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

The description tells the agent how to use the output: 'Use an account's ``id`` for get_balances / get_transactions.' This gives downstream usage context, though it does not explicitly contrast with list_connections or state when not to use this tool.

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

Deploy Server