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 of behavioral disclosure. It states the tool checks for vampire numbers and finds fangs, but doesn't describe what happens for non-vampire numbers (e.g., returns false/empty), performance characteristics, or error handling. For a tool with no annotations, this leaves significant behavioral gaps.

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 extremely concise and front-loaded: it states the core functionality in one clear sentence, followed by domain/category in parentheses. Every word earns its place with no redundancy or fluff, making it easy to parse quickly.

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 (checking a mathematical property), lack of annotations, no output schema, and 0% parameter coverage, the description is insufficient. It doesn't explain the return format (e.g., boolean plus fang pairs), edge cases, or mathematical definition of vampire numbers, leaving the agent with incomplete context for reliable use.

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 1 parameter with 0% description coverage, and the tool description does not explain the parameter 'n' at all. It doesn't specify what 'n' represents (e.g., an integer to test), valid ranges, or constraints. With low schema coverage, the description fails to compensate, leaving the parameter's meaning unclear.

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: 'Check if a number is a vampire number and find its fangs.' It specifies the verb ('check'), resource ('number'), and outcome ('find its fangs'), making the intent unambiguous. However, it does not explicitly differentiate from sibling tools like 'vampire_numbers' (which likely lists vampire numbers), so it misses full sibling distinction.

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. It mentions the domain ('arithmetic') and category ('special_numbers'), but this is generic context that doesn't help an agent choose between this and similar tools (e.g., 'is_vampire_number' vs. 'vampire_numbers'). No explicit when-to-use or when-not-to-use instructions are present.

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