Lunch Money MCP Server

updateBudget

Modify an existing budget's amount, category, or date range in Lunch Money to adjust financial planning parameters.

Instructions

Update an existing budget's amount, category, or date range

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": "updateBudget"
  }
}

Input Schema

Name	Required	Description	Default
`id`	Yes
`category_id`	No
`amount`	No
`currency`	No
`start_date`	No
`end_date`	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?

With no annotations provided, the description carries the full burden of behavioral disclosure. It implies a mutation operation ('Update') but lacks details on permissions, side effects, error handling, or response format. For a tool with 6 parameters and no output schema, this is a significant gap in transparency.

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 that front-loads the core purpose without unnecessary words. Every element ('Update an existing budget's amount, category, or date range') directly contributes to understanding the tool's function.

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 (6 parameters, 0% schema coverage, no annotations, no output schema), the description is inadequate. It doesn't explain parameter semantics fully, lacks behavioral context for a mutation tool, and provides no output information, leaving critical gaps for the agent to operate 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%, so the description must compensate. It lists updatable fields ('amount, category, or date range'), which partially maps to parameters like 'amount', 'category_id', 'start_date', and 'end_date', but omits 'id' (required), 'currency', and details on data formats or constraints. This adds some meaning but doesn't fully address the undocumented parameters.

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 action ('Update') and resource ('an existing budget'), specifying the fields that can be modified ('amount, category, or date range'). It distinguishes from siblings like 'createBudget' by focusing on updates, though it doesn't explicitly differentiate from other update tools like 'updateAsset' or 'updateTransaction' beyond the resource type.

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 budget ID), exclusions, or comparisons to siblings like 'bulkUpdateTransactions' or 'createBudget', leaving the agent to infer usage from the tool name alone.

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