Firefly III MCP Server

Delete Firefly III Category

firefly_delete_category

DestructiveIdempotent

Delete a category from Firefly III. Clears category assignments from existing transactions while preserving transaction data. Use to remove unused categories and reorganize your personal finance structure.

Instructions

Delete a category. Transactions using this category will have their category cleared.

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": "firefly_delete_category"
  }
}

Input Schema

Name	Required	Description	Default
`id`	Yes	Category ID to delete

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.1Apr 7, 2026

TDQS

A4/5.0

Behavior4/5

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

While annotations declare destructiveHint=true, the description adds crucial behavioral context beyond the annotations: specifically that associated transactions are not deleted but rather have their category field cleared. This explains the specific nature of the destruction.

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?

Two sentences total. First states the action; second states the critical side effect. No redundant words or boilerplate. Every sentence earns its place by conveying essential information for a destructive operation.

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

Completeness4/5

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

Adequate for a single-parameter delete operation. The annotations cover the safety profile (destructive, idempotent) and the description covers the business logic side effect. Minor gap: does not describe what the tool returns (success indicator, deleted object, etc.) given no output schema exists.

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?

With 100% schema description coverage, the schema already fully documents the 'id' parameter as 'Category ID to delete.' The description mentions 'Delete a category' which aligns with the parameter but adds no additional semantic detail beyond the schema's explanation.

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?

Description uses specific verb 'Delete' with resource 'category' and distinguishes from sibling tools (delete_account, delete_budget, etc.) by specifying the domain. The second sentence further differentiates by explaining the unique side effect on transactions.

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

Usage Guidelines3/5

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

Provides implied usage guidance by warning that 'Transactions using this category will have their category cleared,' which helps users understand the consequences. However, it lacks explicit when-to-use guidance or comparison to alternatives like firefly_update_category.

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