Random Number MCP

secure_random_int

Generate a cryptographically secure random integer between 0 and a specified upper bound (exclusive).

Instructions

Generate a secure random integer below upper_bound.

Args: upper_bound: Upper bound (exclusive)

Returns: Random integer in range [0, upper_bound)

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": {
      "upper_bound": "<upper_bound>"
    },
    "name": "secure_random_int"
  }
}

Input Schema

Name	Required	Description	Default
`upper_bound`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedv0.1.0May 2, 2026
- removedInput schema / properties / upper_bound / title
```
Removed value: -"Upper Bound"
```
- addedOutput schema / description
```
Added value: +"Generic wrapper for non-object return types."
```
- removedOutput schema / properties / result / title
```
Removed value: -"Result"
```
- removedOutput schema / title
```
Removed value: -"_WrappedResult"
```
First observedv1.0.0Aug 15, 2025

TDQS

A3.9/5.0

Behavior3/5

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

With no annotations, the description must disclose behavior. It states 'secure' (suggesting cryptographic randomness) and defines the output range. However, it does not explain security implications or constraints (e.g., upper_bound must be positive). It is adequate but not comprehensive.

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?

Two sentences with clear purpose and parameter description. Front-loaded with the main action. No wasted words.

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

Completeness4/5

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

For a simple tool with an output schema, the description covers its own behavior and parameters well. However, it lacks guidance on when to use this tool over siblings, slightly reducing completeness.

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

Parameters5/5

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

The schema has 0% parameter coverage, so the description fully compensates by explaining 'upper_bound: Upper bound (exclusive)', adding critical meaning beyond the schema's raw type.

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 the verb 'Generate' and the resource 'secure random integer', with the constraint 'below upper_bound'. This precisely distinguishes it from sibling tools like random_int, which may not emphasize security.

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 guidance on when to use this tool over alternatives like random_int or random_float. The description does not provide context or exclusion criteria.

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

Deploy Server