MCP Math 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. It implies a read-only operation by using 'Get', but does not disclose any behavioral traits such as performance characteristics, error handling, or output format. The description adds some context about the mathematical meaning of tau, but lacks details on how the tool behaves beyond returning a constant value. This is adequate for a simple tool but leaves gaps 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 highly concise and well-structured: it uses a single sentence to state the tool's purpose, provide the constant value, explain its relation to π, and note its mathematical representation. Every part of the sentence adds value, with no wasted words, making it front-loaded and efficient for quick understanding.

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 simplicity (no parameters, no output schema, no annotations), the description is reasonably complete for a constant-fetching tool. It explains what tau is and its value, which is sufficient for basic use. However, it could be more complete by specifying the output format or precision, especially since there is no output schema. The description covers the essentials but leaves some contextual details implicit.

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 input schema has no parameters (parameter count: 0), and schema description coverage is 100%. The description does not need to add parameter semantics, as there are none to document. It appropriately focuses on the tool's purpose without unnecessary parameter details, meeting the baseline for zero parameters.

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 tau (τ) ≈ 6.28318. Equal to 2π, represents a full turn in radians.' It specifies the verb 'Get' and the resource 'tau', with additional context about its mathematical value and significance. However, it does not explicitly differentiate from sibling tools like 'pi' or 'e', which are also mathematical constants, though the distinction is implied by the different constant values.

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 minimal usage guidance: it mentions the domain ('arithmetic') and category ('general'), but does not specify when to use this tool versus alternatives. For example, it does not explain when to use 'tau' instead of 'pi' or other constants, nor does it provide any exclusions or prerequisites. The guidance is vague and lacks explicit context for tool selection.

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