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. 'Create' implies a write/mutation operation, but the description doesn't mention permissions required, whether this operation is idempotent, what happens on failure, or what the response contains. For a creation tool with 7 parameters and no output schema, this is a significant gap in behavioral context.

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 maximally concise - a single sentence with no wasted words. While it's under-specified, it's not verbose or poorly structured. Every word earns its place, though more content would be beneficial for this complex tool.

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 creation tool with 7 parameters, no annotations, no output schema, and 0% schema description coverage, the description is severely incomplete. The agent needs to understand what a 'category group' is, how it differs from individual categories, what parameters are most important, and what to expect as a result. The current description provides none of this contextual information.

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. With 0% schema description coverage (the schema has no descriptions at the top level), the agent has no semantic understanding of what 'input' represents or what's required to create a category group. The description doesn't mention that 'name' is required or explain the relationship between 'category_ids' and 'new_categories'.

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 'Create a single category group' states the basic action (create) and resource (category group), but it's vague about what a 'category group' actually is in this financial context. It doesn't distinguish this from sibling tools like 'create_category' or 'add_to_category_group' - the agent won't understand when to create a category versus a category group.

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. With sibling tools like 'create_category', 'add_to_category_group', and 'update_category', the agent has no indication of when creating a category group is appropriate versus creating individual categories or modifying existing ones. The description offers no context about prerequisites or typical use cases.

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