NPM Sentinel MCP

npmTypes

Read-onlyIdempotent

Verify whether NPM packages include TypeScript definitions and retrieve the available type version.

Instructions

Check TypeScript types availability and version for a package

Input Schema

TableJSON Schema

Name	Required	Description	Default
`packages`	Yes	List of package names to check types for
`ignoreCache`	No	Force a fresh lookup, ignoring the cache

Output Schema

TableJSON Schema

Name	Required	Description	Default
`message`	No
`results`	No
`summary`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.24.0Jul 28, 2026

changedInput schema / $schema

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "additionalProperties": {},
+  "properties": {
+    "message": {
+      "type": "string"
+    },
+    "results": {
+      "items": {
+        "additionalProperties": {},
+        "propertyNames": {
+          "type": "string"
+        },
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "summary": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "additionalProperties": {},
+          "propertyNames": {
+            "type": "string"
+          },
+          "type": "object"
+        }
+      ]
+    }
+  },
+  "type": "object"
+}

Changed2 schema fields changedv1.23.0Jul 25, 2026
- addedInput schema / properties / packages / maxItems
```
Added value: +25
```
- addedInput schema / properties / packages / minItems
```
Added value: +1
```
Changed2 schema fields changedv1.20.0Jul 13, 2026
- removedInput schema / additionalProperties
```
Removed value: -false
```
- addedInput schema / properties / ignoreCache
```
Added value: +{
+  "description": "Force a fresh lookup, ignoring the cache",
+  "type": "boolean"
+}
```
First observedv1.0.0Aug 14, 2025

TDQS

A3.6/5.0

Behavior3/5

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description adds minimal behavioral context; it doesn't mention caching behavior or the ability to check multiple packages (despite schema allowing array). No contradiction with annotations.

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 a single, front-loaded sentence with no wasted words. It is concise but could be slightly improved by clarifying plural packages.

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?

Given the existence of an output schema, the description does not need to explain return values. However, it lacks contextual hints such as typical use cases or edge cases, making it adequate but not rich.

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 100%, so the schema already documents both parameters. The description adds no additional meaning beyond what the schema provides, meeting the baseline score of 3.

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 'Check' and the resource 'TypeScript types availability and version for a package'. It distinguishes this tool from siblings like npmVersions and npmLatest by focusing specifically on type availability, not general version info.

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

Usage Guidelines3/5

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

The description does not explicitly state when to use this tool versus alternatives. Given the sibling tools, the name suggests its purpose, but no when-not-to-use or alternative guidance is provided.

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