FactGrid (Renamed to FactReason)

API breaking changes

factreason_api_breaking_changes

Read-onlyIdempotent

Compare two versions of a third-party API and return breaking changes, including removed endpoints, parameter type changes, removed request body fields, and migration guides. Use factreason_package_upgrade_advisory for npm or PyPI packages.

Input Schema

TableJSON Schema

Name	Required	Description
`apiKey`	No	Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a key that belongs to someone else.
`service`	Yes	Third-party API service, e.g. "Stripe" or "OpenAI"
`toVersion`	No	Optional exact version being evaluated
`fromVersion`	No	Optional exact version currently targeted

Output Schema

TableJSON Schema

Name	Required	Description	Default
`found`	No
`billed`	No
`changes`	No
`meaning`	No
`message`	No
`service`	No
`suggestion`	No
`changeCount`	No
`alternatives`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedOct 4, 2026

addedInput schema / properties / apiKey

Added value: +{
+  "description": "Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a key that belongs to someone else.",
+  "maxLength": 128,
+  "minLength": 1,
+  "type": "string"
+}

Changed8 schema fields changedAug 14, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

changedInput schema / properties / fromVersion / description

Previous value: -"Optional: version currently targeted"New value: +"Optional exact version currently targeted"

addedInput schema / properties / fromVersion / minLength
```
Added value: +1
```

changedInput schema / properties / service / description

Previous value: -"Service name, e.g. \"Stripe\", \"OpenAI\", \"Supabase\""New value: +"Third-party API service, e.g. \"Stripe\" or \"OpenAI\""

addedInput schema / properties / service / minLength
```
Added value: +1
```

changedInput schema / properties / toVersion / description

Previous value: -"Optional: version being upgraded to"New value: +"Optional exact version being evaluated"

addedInput schema / properties / toVersion / minLength
```
Added value: +1
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "additionalProperties": true,
+  "properties": {
+    "alternatives": {
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "billed": {
+      "type": "boolean"
+    },
+    "changeCount": {
+      "type": "number"
+    },
+    "changes": {
+      "items": {
+        "additionalProperties": true,
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "found": {
+      "type": "boolean"
+    },
+    "meaning": {
+      "type": "string"
+    },
+    "message": {
+      "type": "string"
+    },
+    "service": {
+      "type": "string"
+    },
+    "suggestion": {
+      "type": "string"
+    }
+  },
+  "type": "object"
+}

AddedAug 14, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already declare this a safe, idempotent read (readOnlyHint, destructiveHint=false), so the safety profile is covered. The description adds real behavioral value by specifying the analysis performed (version diffing for breaking changes) and that migration guides are produced. Return format is not described, but an output schema exists, so that omission is acceptable.

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, both earning their place: the first defines capability and outputs, the second handles sibling routing. The core purpose is front-loaded with no preamble or filler.

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?

With an output schema present, annotations covering safety, and 100% parameter description coverage, the description carries everything an agent needs: what the tool analyzes, what it returns, and which sibling to use instead. No meaningful gap remains.

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 all four parameters (apiKey, service, fromVersion, toVersion) are documented in the schema itself. The description only implies the two-version comparison and adds no syntax, defaults, or examples beyond what the schema provides, so the baseline of 3 applies.

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?

States a specific verb and resource ('Compare two versions of a third-party API') and enumerates the concrete outputs (removed endpoints, parameter type changes, removed request body fields, migration guides). It also names the sibling it is not (factreason_package_upgrade_advisory), so an agent can distinguish it without opening any schema.

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

Usage Guidelines4/5

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

Explicitly routes the agent away from this tool for npm/PyPI packages by naming factreason_package_upgrade_advisory, which is a clear alternative. However it gives no guidance on when to prefer this over other version-related siblings such as factreason_deprecation_scan.

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

All FactGrid (Renamed to FactReason) tools Inspect

Try in Browser

Shareable, User-Owned Context BackendPeople, applications, and agents read, write, and coordinate together in one context lake. Reach it over MCP, a CLI, a Python SDK, or REST.fulcradynamics.comAd

Glama MCP Gateway

Add one secure layer between your agents and this server.