Expense Tracker MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the month parameter format and default, which is useful, but doesn't describe key behaviors such as what data is returned (e.g., comparison details, error handling), whether it's a read-only operation, or any performance considerations. For a tool with no annotation coverage, this is a significant gap.

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 highly concise and front-loaded, consisting of two clear sentences that directly state the tool's purpose and parameter details without any wasted words. Every sentence earns its place by providing essential information efficiently.

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 (one parameter, no annotations, but with an output schema), the description is minimally adequate. It covers the basic purpose and parameter semantics, but since there's an output schema, it doesn't need to explain return values. However, for a tool with no annotations, it could benefit from more behavioral context to be fully complete.

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 adds meaningful context for the single parameter by specifying the month format ('YYYY-MM') and default behavior ('defaults to current month'), which goes beyond the input schema's minimal coverage (0% schema description coverage). Since there's only one parameter, this effectively compensates for the schema's lack of detail, though it doesn't fully explain all possible semantics.

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 with a specific verb ('Compare') and resources ('budget limits vs actual spend'), making it immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'get_expense_summary' or 'list_expenses', which might also involve budget/spend analysis, so it doesn't reach the highest score.

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 implies usage by specifying the month parameter format and default, suggesting it's for checking budget status in a given month. However, it doesn't provide explicit guidance on when to use this tool versus alternatives like 'get_expense_summary' or 'list_expenses', nor does it mention prerequisites or exclusions, leaving usage context somewhat vague.

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