Firefly III MCP Server

Delete Firefly III Transaction

firefly_delete_transaction

DestructiveIdempotent

Delete a specific transaction permanently from Firefly III using its group ID. Remove financial records that cannot be undone.

Instructions

Permanently delete a transaction by its ID. This action cannot be undone.

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_transaction"
  }
}

Input Schema

Name	Required	Description	Default
`id`	Yes	Transaction group ID to delete

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.1Apr 7, 2026

TDQS

A3.8/5.0

Behavior3/5

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

Annotations already declare destructiveHint=true and readOnlyHint=false. The description reinforces this safety profile by emphasizing 'permanently' and 'cannot be undone,' adding valuable consequence context. However, it omits discussion of idempotentHint=true behavior (safe to retry) or openWorldHint=true implications.

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 with zero waste: the first establishes the operation and target, the second provides the critical irreversibility warning. Information is front-loaded and appropriately sized for a single-parameter 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?

Given the simple single-parameter input schema and absence of output schema requirements, the description is complete. It adequately covers the operation's intent and irreversible nature, though it could briefly mention that the ID refers to a transaction group as noted in the schema.

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 ('Transaction group ID to delete'), the schema carries the full semantic load. The description references 'by its ID' which aligns with the schema, meeting the baseline expectation without adding redundant parameter details.

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 clearly states the specific action (permanently delete), target resource (transaction), and identifier method (by its ID). It effectively distinguishes from sibling tools like update_transaction or search_transactions through the explicit 'permanently' and 'delete' verbs.

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?

The warning 'This action cannot be undone' provides implied guidance about irreversibility and caution, but lacks explicit when-to-use criteria or named alternatives (e.g., suggesting update_transaction for corrections vs. deletion).

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