GST Insights API MCP Server

validate_gst_number

Validates a 15-character GST number and returns registration status and details. Input a GST number to verify its authenticity.

Instructions

Endpoint: /validateGSTNumber/:gst Method: GET Description: Validates the provided GST number. Parameters: gst (string, required): A valid GST number (15 characters). Responses: 200 OK: Returns validation results along with a timestamp. 400 Bad Request: Invalid GST number. 500 Internal Server Error: An error occurred on the server. GET /validateGSTNumber/22ABCDE1234F1Z5

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": {
      "GSTNumber": "<GSTNumber>"
    },
    "name": "validate_gst_number"
  }
}

Input Schema

Name	Required	Description	Default
`GSTNumber`	Yes	Example value: 27AABCI6363G3ZH

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Mar 5, 2026

TDQS

A3.7/5.0

Behavior3/5

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

No annotations provided. The description mentions the GET method (implying read-only) and lists response codes (200, 400, 500) with brief meanings, but does not disclose side effects, authentication needs, or rate limits. Adequate but minimal behavioral context.

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

Conciseness4/5

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

The description is well-structured with sections for endpoint, method, parameters, and responses. It is somewhat lengthy due to the example, but the key purpose is front-loaded. Slightly verbose but effective.

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?

With no output schema, the description adequately explains return types (validation results with timestamp) and error responses. For a single-parameter tool, it provides sufficient context, though the response structure could be more detailed.

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

Parameters4/5

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

Schema coverage is 100% with one parameter. The description adds meaning by specifying the required length (15 characters) and providing an example usage in the endpoint, though there is a mismatch between the description parameter name 'gst' and schema property 'GSTNumber'.

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 validates a GST number, with specific verb and resource. It distinguishes from sibling tools (e.g., get_gst_details_using_gst_number) by focusing on validation rather than retrieval of details.

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 versus siblings. For example, it does not say to use this for validation only and other tools for detailed information. The description is purely technical.

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

Deploy Server