YNAB MCP Server

Get Income Expense Summary

get_income_expense_summary

Read-onlyIdempotent

Calculate monthly income vs. spending and savings rate from YNAB transaction history, excluding transfers and deleted transactions, to answer savings-rate and trend questions.

Instructions

Read-only income vs. spending summary by month, computed from transaction history. Income counts non-transfer inflows to 'Inflow: Ready to Assign'; spending counts non-transfer outflows; transfers and deleted transactions are excluded, so credit card payments do not double-count. Includes per-month savings rate ((income - spending) / income). Use for savings-rate reports, month-end closes, and trend questions like 'am I saving enough'. Refunds appear as negative spending months' offsets, not income.

Input Schema

TableJSON Schema

Name	Required	Description
`budgetId`	No	Budget ID (uses default if not provided)
`sinceDate`	No	Start of the window (YYYY-MM-DD). Defaults to 6 full months back.
`untilDate`	No	End of the window (YYYY-MM-DD). Defaults to today.

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 Income Expense Summary."
```
Addedv5.1.1Jul 21, 2026

TDQS

A4.5/5.0

Behavior5/5

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

The description adds substantial behavioral detail beyond the annotations: it explains computation rules (income/spending definitions, exclusion of transfers and deleted transactions, savings-rate formula, refunds as negative spending offsets). The 'Read-only' wording is consistent with readOnlyHint=true, and the extra context about double-counting and refund handling is valuable.

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?

Every sentence in the description earns its place: the core summary is front-loaded, followed by precise counting rules, the savings-rate definition, explicit use cases, and an edge-case clarification about refunds. The five sentences are justified by the tool's computational complexity and remain tightly structured.

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?

With an output schema present, return values need no explanation here. The description covers the tool's purpose, exact calculation methodology, exclusions, refund behavior, and usage guidance, leaving no critical gap for an agent to select and invoke it correctly.

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

Parameters3/5

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

Input schema covers all three parameters with clear descriptions and 100% coverage, so the baseline is 3. The tool description adds no parameter-level semantics beyond what the schema already states; it references monthly windows but does not detail date formatting or defaults.

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 opens with a precise verb and resource: 'Read-only income vs. spending summary by month, computed from transaction history.' It further defines the exact income and spending scope (non-transfer inflows/outflows) and clearly differentiates this tool from siblings like get_transactions or get_budget_health by focusing on monthly summary with savings-rate calculation.

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 explicitly states applicable contexts: 'Use for savings-rate reports, month-end closes, and trend questions like

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