Skip to main content
Glama
Jambozx

OnlineCyberTools MCP (280+ filterable tools)

by Jambozx
OverviewSchemaRelated ServersScoreDiscussions
JavaScript
Remote

data_json_schema_validator

Read-onlyIdempotent

Validates JSON data against a JSON Schema using Ajv, reporting all constraint failures with keyword, path, and message. Detects schema version from $schema URI.

Instructions

JSON Schema Validator (Draft 2020-12, Ajv). Validate a JSON instance against a JSON Schema (Draft 2020-12 by default; 2019-09, 7, 6, 4 are recognised from the schema $schema URI) using Ajv with ajv-formats, and report every constraint failure. Use this to check data you already have against a schema you already have; use data_json_schema_generator instead to infer a schema from a sample document. Compiles and validates locally on the input you provide: read-only, non-destructive, contacts no external service and does not fetch remote $ref schemas over the network, and is rate-limited (60 requests/minute for anonymous callers). Returns a valid flag and an errors array (each with keyword, instancePath, schemaPath, and message) plus an error count and the detected schema version.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
schemaYesJSON Schema to validate against, as an object/boolean or a raw-JSON string. Draft is auto-detected from its $schema URI (defaults to Draft 2020-12).
instanceYesJSON document to validate. Accepts a parsed value (object, array, number, boolean, null) or a raw-JSON string, which is parsed when it looks like JSON.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
successNoTrue when validation ran (independent of whether the instance was valid).
operationNoAlways validate.
resultNoThe validation result payload.

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. Changed10 schema fields changedv0.5.1
    • addedInput schema / additionalProperties
      Added value: +false
    • addedInput schema / properties / instance / description
      Added value: +"JSON document to validate. Accepts a parsed value (object, array, number, boolean, null) or a raw-JSON string, which is parsed when it looks like JSON."
    • removedInput schema / properties / instance / properties
      Removed value: -{
-  "age": {
-    "type": "integer"
-  },
-  "name": {
-    "type": "string"
-  }
-}
    • removedInput schema / properties / instance / required
      Removed value: -[
-  "name",
-  "age"
-]
    • changedInput schema / properties / instance / type
      Previous value: -"object"New value: +[
+  "object",
+  "array",
+  "string",
+  "number",
+  "boolean",
+  "null"
+]
    • addedInput schema / properties / schema / description
      Added value: +"JSON Schema to validate against, as an object/boolean or a raw-JSON string. Draft is auto-detected from its $schema URI (defaults to Draft 2020-12)."
    • removedInput schema / properties / schema / properties
      Removed value: -{
-  "properties": {
-    "properties": {
-      "age": {
-        "properties": {
-          "type": {
-            "type": "string"
-          }
-        },
-        "required": [
-          "type"
-        ],
-        "type": "object"
-      },
-      "name": {
-        "properties": {
-          "type": {
-            "type": "string"
-          }
-        },
-        "required": [
-          "type"
-        ],
-        "type": "object"
-      }
-    },
-    "required": [
-      "name",
-      "age"
-    ],
-    "type": "object"
-  },
-  "required": {
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  },
-  "type": {
-    "type": "string"
-  }
-}
    • removedInput schema / properties / schema / required
      Removed value: -[
-  "type",
-  "required",
-  "properties"
-]
    • changedInput schema / properties / schema / type
      Previous value: -"object"New value: +[
+  "object",
+  "string",
+  "boolean"
+]
    • changedOutput schema / (root)
      Previous value: -nullNew value: +{
+  "properties": {
+    "operation": {
+      "description": "Always validate.",
+      "type": "string"
+    },
+    "result": {
+      "description": "The validation result payload.",
+      "properties": {
+        "errorCount": {
+          "description": "Number of entries in errors (0 when valid).",
+          "type": "integer"
+        },
+        "errors": {
+          "description": "One entry per constraint violation; empty when valid.",
+          "items": {
+            "properties": {
+              "instancePath": {
+                "description": "JSON Pointer to the offending location in the instance.",
+                "type": "string"
+              },
+              "keyword": {
+                "description": "Failing JSON Schema keyword (type, required, enum, pattern, and similar).",
+                "type": "string"
+              },
+              "message": {
+                "description": "Human-readable Ajv error message.",
+                "type": "string"
+              },
+              "params": {
+                "description": "Keyword-specific detail (allowed values, limits, missing property).",
+                "type": "object"
+              },
+              "schemaPath": {
+                "description": "JSON Pointer to the failing keyword in the schema.",
+                "type": "string"
+              }
+            },
+            "type": "object"
+          },
+          "type": "array"
+        },
+        "schemaVersion": {
+          "description": "Detected schema draft label, for example Draft 2020-12.",
+          "type": "string"
+        },
+        "valid": {
+          "description": "True when the instance satisfies the schema.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "success": {
+      "description": "True when validation ran (independent of whether the instance was valid).",
+      "type": "boolean"
+    }
+  },
+  "type": "object"
+}
  2. First observedv0.1.0

TDQS

A4.8/5.0
Behavior5/5

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

Annotations already declare read-only, non-destructive, idempotent. Description adds important context: local compilation, no remote $ref fetching, rate limit (60 req/min). No contradiction.

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?

Description is fairly concise but slightly verbose; each sentence adds value but could be more tightly written. Front-loads purpose well.

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

Completeness5/5

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

Covers supported drafts, behavior with remote $ref, rate limits, and output structure (valid flag, errors array with fields). Output schema exists but description adds context.

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%, so baseline is 3. Description adds auto-detection of draft from $schema and notes that instance can be parsed or raw string, going beyond schema.

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 JSON instance against a JSON Schema using Ajv, and distinguishes from data_json_schema_generator which infers schemas.

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

Usage Guidelines5/5

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

Explicitly says when to use this tool ('to check data you already have against a schema you already have') and when to use the sibling tool instead.

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

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/Jambozx/onlinecybertools-mcp-server'

If you have feedback or need assistance with the MCP directory API, please join our Discord server