LunchMoney MCP Server

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

With no annotations provided, the description carries full burden but only states it's an update operation. It doesn't disclose critical behavioral traits like whether this is a destructive mutation, what permissions are required, how errors are handled, whether it's idempotent, or what happens to related data (e.g., account balances). The description is minimal and leaves the agent guessing about important operational characteristics.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise at just 4 words with no wasted language. It's front-loaded with the core action and resource. While arguably too brief, it achieves maximum efficiency per word count.

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

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

For a mutation tool with no annotations, no output schema, complex nested parameters, and 0% schema description coverage, this description is completely inadequate. It doesn't explain what the tool returns, what side effects occur, error conditions, or provide any meaningful context beyond the basic verb-noun pairing.

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

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

The description provides zero information about parameters beyond what's implied by 'update an existing transaction'. With 0% schema description coverage and 1 parameter (a complex nested object), the description fails to compensate for the schema's lack of parameter documentation. It doesn't mention the required transaction_id, the transaction object structure, or any of the 12+ nested fields.

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

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

The description 'Update an existing transaction' clearly states the action (update) and resource (transaction), but it's vague about scope and doesn't differentiate from sibling tools like 'update_asset' or 'update_category'. It doesn't specify what aspects of a transaction can be updated or the system context.

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

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

No guidance is provided about when to use this tool versus alternatives. There's no mention of prerequisites (e.g., needing an existing transaction ID), when not to use it, or how it differs from related tools like 'create_transactions' or 'get_transactions'.

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