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. While 'Delete' implies a destructive mutation, the description doesn't specify whether this action is reversible, requires specific permissions, has side effects (e.g., on budget calculations), or returns confirmation details. For a destructive tool with zero annotation coverage, this is a significant gap in transparency.

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, direct sentence with zero wasted words, making it highly concise and front-loaded. Every word ('Delete an expense by ID') contributes essential information, achieving optimal efficiency for such a simple 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?

Given the tool's complexity (a destructive mutation), lack of annotations, and presence of an output schema (which reduces the need to describe return values), the description is minimally adequate. It states the core action but misses critical context like behavioral traits, usage guidelines, and parameter details, making it incomplete for safe and effective use by an agent.

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 schema description coverage is 0%, but the description adds minimal semantic context by specifying that the 'id' parameter is used to identify the expense to delete. However, it doesn't explain what format the ID should be (e.g., integer, string) or where to find it, leaving the schema to carry most of the parameter documentation burden. With one parameter, the baseline is 4, but the lack of detail reduces this to 3.

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 ('Delete') and target resource ('an expense by ID'), making the purpose immediately understandable. However, it doesn't differentiate this tool from sibling tools like 'update_expense' or 'list_expenses' beyond the basic verb, which prevents a perfect 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 provides no guidance on when to use this tool versus alternatives like 'update_expense' or 'list_expenses'. It lacks context about prerequisites (e.g., whether the expense must exist), exclusions, or recommended workflows, leaving the agent to infer usage from the tool name alone.

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