Math-MCP

by PolarisHub

Overview Schema Source Related Servers Discussions Admin

TypeScript

percentage_change

Calculate the percentage increase or decrease between two numerical values.

Instructions

Calculates the percentage increase or decrease from an original value to a new value

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "originalValue": "<originalValue>",
      "newValue": "<newValue>"
    },
    "name": "percentage_change"
  }
}

Input Schema

Name	Required	Description	Default
`newValue`	Yes
`originalValue`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.0Jul 28, 2026

TDQS

A3.7/5.0

Behavior4/5

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

With no annotations provided, the description bears full responsibility. It correctly describes a pure computation (no side effects), but lacks detail on edge cases like division by zero. However, the core behavior is transparent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single, front-loaded sentence with no wasted words. The verb 'calculates' immediately conveys action, and the structure is efficient.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Adequate for a simple tool, but missing details on return format, error handling (e.g., originalValue=0), and additional behavioral context. With no output schema, the description could be more complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The description maps parameters via 'from an original value to a new value', indicating which is which. However, schema description coverage is 0%, and the description adds no constraints, types, or examples beyond the basic mapping.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it calculates percentage change from original to new value. It distinguishes from sibling 'percentage_of', which calculates proportion, making the tool's specific purpose unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No explicit guidance on when to use this tool versus alternatives like 'percentage_of'. The description only states what it does, leaving the agent to infer usage context without help.

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