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 for behavioral disclosure. It states this is an update operation, implying mutation, but doesn't address permissions needed, whether changes are reversible, error conditions, or what happens to unspecified properties. For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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 a single, efficient sentence that states the core purpose without unnecessary words. It's appropriately sized for a tool with comprehensive parameter documentation in the schema.

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 and no output schema, the description is insufficient. It doesn't address what happens on success/failure, what permissions are required, whether the update is atomic, or how to verify changes. Given the complexity of updating financial categories with multiple properties, more context is needed.

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 mentions 'properties' but doesn't specify which properties can be updated or their semantics. With 0% schema description coverage, the input schema provides all parameter documentation. The description adds no meaningful parameter information beyond what's already in the schema, meeting the baseline for when schema does the heavy lifting.

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 clearly states the action ('Update') and target ('properties for a single category or category group'), making the purpose immediately understandable. However, it doesn't explicitly differentiate this tool from sibling tools like 'update_asset' or 'update_transaction', which also perform updates on different resources.

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?

The description provides no guidance on when to use this tool versus alternatives like 'create_category' or 'delete_category'. While the input schema mentions executing 'get_all_categories' first to obtain category IDs, this is parameter documentation rather than usage guidance for the tool itself.

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