YNAB MCP Server

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

With no annotations provided, the description carries the full burden. It discloses the tool's read-only nature implicitly by using 'Get' and describes the return structure, but lacks details on permissions, rate limits, error handling, or data freshness. It adds some behavioral context but not comprehensively.

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 well-structured and front-loaded with the purpose, followed by clear sections for Args and Returns. Every sentence adds value: the purpose statement, parameter explanations with examples, and return details. No wasted words.

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?

Given the tool's moderate complexity (2 parameters, no annotations, but has an output schema), the description is fairly complete. It covers purpose, parameter semantics, and return values. However, it lacks usage guidelines and some behavioral details like error cases or dependencies, leaving minor gaps.

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?

Schema description coverage is 0%, so the description must compensate. It adds meaningful semantics: 'month' is explained as 'Month in YYYY-MM-DD format (first of month)' with an example and default, and 'budget_id' is clarified with 'uses default if omitted.' This provides essential context beyond the bare schema.

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 tool's purpose: 'Get a monthly budget summary with category breakdowns.' It specifies the verb ('Get') and resource ('monthly budget summary'), but doesn't explicitly differentiate from sibling tools like 'get_budget_months' or 'get_budgets' that might also retrieve budget-related data.

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 on when to use this tool versus alternatives. While it mentions defaults for parameters, it doesn't specify scenarios for usage, prerequisites, or exclusions compared to siblings like 'get_budget_months' or 'get_budgets'.

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