BuildMcpServer

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

No annotations are provided, so the description carries full burden. It states the basic operation but lacks behavioral details like error handling for non-numeric inputs, precision limits, or performance characteristics. The description doesn't disclose any behavioral traits beyond the core functionality.

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 appropriately sized and front-loaded with the core operation in the first sentence. The Args and Returns sections are structured efficiently with zero wasted words, making every sentence earn its place.

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 low complexity (simple arithmetic), 2 parameters, and the presence of an output schema (which handles return values), the description is reasonably complete. It covers the operation and parameter meanings adequately, though it lacks some behavioral context that would be helpful without annotations.

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 clearly explains parameter semantics: 'a' as 'Number to subtract from' and 'b' as 'Number to subtract', adding meaning beyond the schema's generic titles. However, it doesn't specify constraints like number types (integer vs float) or ranges.

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 states a specific verb ('subtract') and resource ('the second number from the first'), clearly defining the mathematical operation. It distinguishes from siblings (add, divide, multiply) by specifying subtraction rather than other arithmetic operations.

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 for subtraction calculations but provides no explicit guidance on when to use this tool versus alternatives like 'add' or 'multiply'. No context about when-not-to-use or prerequisites is mentioned.

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