MCP Server Demo

by dynstat

Overview Schema Source Related Servers Discussions Admin

Python

Remote

add

Calculate the sum of two integer values. Enter two numbers to get their total result.

Instructions

Add two numbers

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": {
      "a": "<a>",
      "b": "<b>"
    },
    "name": "add"
  }
}

Input Schema

Name	Required	Description	Default
`a`	Yes
`b`	Yes

Implementation Reference

server.py:108-111 (handler)
The handler function for the 'add' tool, decorated with @mcp.tool() for registration in the MCP server. It takes two integers a and b, adds them, and returns the result. The type hints serve as the input schema.
```
@mcp.tool()
def add(a: int, b: int) -> int:
    """Add two numbers"""
    return a + b
```

Schema Changelog

Changes observed during successful MCP inspections.

First observedAug 18, 2025

TDQS

C2.9/5.0

Behavior2/5

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. 'Add two numbers' implies a simple computation but doesn't address potential issues like integer overflow, error handling, or output format. For a tool with zero annotation coverage, 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.

Conciseness5/5

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

The description is extremely concise at three words, with zero wasted text. It's front-loaded and directly states the tool's function without unnecessary elaboration, making it efficient and easy to parse.

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

Completeness2/5

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

Given the tool's simplicity (2 parameters, no annotations, no output schema), the description is minimal but inadequate. It doesn't explain the return value (e.g., sum as integer), error cases, or behavioral nuances. For even a simple tool, more context would improve agent understanding.

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?

Schema description coverage is 0%, so the schema provides no parameter descriptions. The description 'Add two numbers' implies the parameters are numbers to be added, which adds basic semantic meaning beyond the schema's type definitions. However, it doesn't specify parameter roles (e.g., which is first/second) or constraints, leaving some ambiguity.

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

Purpose4/5

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

The description 'Add two numbers' clearly states the verb ('Add') and resource ('two numbers'), making the purpose immediately understandable. It doesn't distinguish from sibling tools (fetch_news_articles, get_weather) since they're unrelated, but the purpose is specific and 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?

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention any context, prerequisites, or exclusions. While the sibling tools are unrelated, the description offers no usage instructions beyond the basic operation.

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

Deploy Server

add