Lunch Money MCP Server

updateCategory

Modify existing financial categories in Lunch Money by updating properties like name, description, budget exclusions, or parent relationships to maintain accurate expense tracking.

Instructions

Update an existing category's properties

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": {
      "id": "<id>"
    },
    "name": "updateCategory"
  }
}

Input Schema

Name	Required	Description	Default
`id`	Yes
`name`	No
`description`	No
`is_income`	No
`exclude_budget`	No
`exclude_from_totals`	No
`archived`	No
`category_group_id`	No
`parent_category_id`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jan 28, 2026

TDQS

C2.8/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states 'Update' which implies a mutation, but doesn't cover critical aspects like required permissions, whether changes are reversible, error handling, or response format. This is inadequate for a mutation tool with zero annotation coverage.

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 a single, efficient sentence with zero waste. It's front-loaded and appropriately sized for the tool's complexity, making it easy to parse quickly.

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?

Given the complexity (9 parameters, mutation operation, no annotations, no output schema), the description is incomplete. It lacks details on parameters, behavioral traits, and usage context, making it insufficient for an agent to effectively select and invoke this tool.

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%, meaning none of the 9 parameters are documented in the schema. The description only mentions 'properties' generically without explaining any specific parameters (e.g., 'id', 'name', 'is_income'), failing to compensate for the coverage gap and leaving most semantics unclear.

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

Purpose4/5

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

The description clearly states the verb ('Update') and resource ('an existing category's properties'), making the purpose understandable. However, it doesn't differentiate from sibling tools like 'updateBudget' or 'updateTransaction', which follow the same pattern for different resources, so it lacks sibling differentiation.

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?

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an existing category ID), exclusions, or comparisons to siblings like 'createCategory' or 'deleteCategory', leaving the agent with no usage context.

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