YNAB MCP Server

Get Transaction

get_transaction

Read-onlyIdempotent

Fetch a single YNAB transaction by ID, with special handling for composite scheduled-transaction IDs that return the scheduled template if the matched transaction is missing.

Instructions

Get a single transaction by ID. The argument is 'transactionId' (not 'id'). Automatically handles composite scheduled-transaction IDs (e.g. uuid_YYYY-MM-DD): the date suffix is stripped before the lookup. If a composite ID's underlying matched transaction has been deleted, falls back to returning the active scheduled-transaction template wrapped in a marker shape { resource_type: 'scheduled_transaction', reason: 'composite_id_with_no_matched_transaction', scheduled_transaction, requested_id } so callers can distinguish the two return shapes. Non-composite IDs preserve strict behavior: a 404 still surfaces as resource_not_found.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`budgetId`	No	Budget ID (uses default if not provided)
`transactionId`	Yes	Transaction ID

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv5.4.0Sep 15, 2026
- removedOutput schema / properties / result / description
```
Removed value: -"Structured result returned by Get Transaction."
```

Changed1 schema field changedv5.1.1Jul 21, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": false,
+  "properties": {
+    "result": {
+      "description": "Structured result returned by Get Transaction."
+    }
+  },
+  "required": [
+    "result"
+  ],
+  "type": "object"
+}

First observedv2.0.0May 28, 2026

TDQS

A4.8/5.0

Behavior5/5

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

Annotations declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds substantial behavioral detail: automatic composite ID handling, fallback to scheduled-transaction template with a marker shape, and strict behavior for non-composite IDs. It also clarifies the exact return shapes and error behavior, going well beyond annotations.

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 dense but every sentence earns its place. It front-loads the core purpose, then details composite handling and return shapes. No fluff, well-structured, and easy to parse despite its length.

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's complexity (composite IDs, fallback behavior, two return shapes), the description is thorough. The output schema covers return values, and the description covers all edge cases and special handling. Nothing an agent needs to call this correctly is missing.

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

Parameters5/5

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

Schema coverage is 100%, but the description adds crucial semantics: it explicitly warns that the argument is 'transactionId' (not 'id'), explains the composite ID format and stripping, and describes the fallback logic. This adds meaning that the schema alone doesn't provide.

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 states 'Get a single transaction by ID' – a specific verb and resource. It clearly differentiates from siblings like get_transactions and search_transactions by focusing on a single transaction via ID, and even clarifies the argument name. No ambiguity.

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 implies when to use (single transaction lookup) but doesn't explicitly name alternatives. However, it provides critical context on composite vs. non-composite IDs, which guides appropriate usage. It's clear enough for an agent to infer the right tool, though explicit exclusions would push it to a 5.

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