MCP Firebird

subscribe_to_event

subscribe_to_event

Idempotent

Register a Firebird POST_EVENT listener to receive database event notifications; also requires MCP resource subscription for delivery.

Instructions

Input Schema

TableJSON Schema

Name	Required	Description	Default
`eventName`	Yes

Output Schema

TableJSON Schema

Name	Required	Description
`error`	No	Failure information; present when success is false
`result`	No	The legacy JSON payload; present for completed operations and partial batches
`success`	Yes	False for tool failures, including partially failed batches

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedv2.12.0Oct 7, 2026

changedInput schema / $schema

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

removedInput schema / additionalProperties
```
Removed value: -false
```

removedInput schema / properties / eventName / description

Removed value: -"The name of the Firebird event to subscribe to (e.g. 'NEW_ORDER', 'CLIENT_UPDATED')"

addedInput schema / properties / eventName / maxLength
```
Added value: +127
```
addedInput schema / properties / eventName / minLength
```
Added value: +1
```
addedInput schema / properties / eventName / pattern
```
Added value: +"^[^\\u0000-\\u001f\\u007f]+$"
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$defs": {
+    "__schema0": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "number"
+        },
+        {
+          "type": "boolean"
+        },
+        {
+          "type": "null"
+        },
+        {
+          "items": {
+            "$ref": "#/$defs/__schema0"
+          },
+          "type": "array"
+        },
+        {
+          "additionalProperties": {
+            "$ref": "#/$defs/__schema0"
+          },
+          "propertyNames": {
+            "type": "string"
+          },
+          "type": "object"
+        }
+      ]
+    }
+  },
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "additionalProperties": false,
+  "properties": {
+    "error": {
+      "additionalProperties": false,
+      "description": "Failure information; present when success is false",
+      "properties": {
+        "details": {
+          "additionalProperties": {
+            "$ref": "#/$defs/__schema0"
+          },
+          "propertyNames": {
+            "type": "string"
+          },
+          "type": "object"
+        },
+        "message": {
+          "type": "string"
+        },
+        "type": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "message",
+        "type"
+      ],
+      "type": "object"
+    },
+    "result": {
+      "additionalProperties": false,
+      "description": "The legacy JSON payload; present for completed operations and partial batches",
+      "properties": {
+        "eventName": {
+          "type": "string"
+        },
+        "registered": {
+          "type": "boolean"
+        },
+        "subscriptionAction": {
+          "enum": [
+            "open",
+            "close"
+          ],
+          "type": "string"
+        },
+        "uri": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "eventName",
+        "uri"
+      ],
+      "type": "object"
+    },
+    "success": {
+      "description": "False for tool failures, including partially failed batches",
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success"
+  ],
+  "type": "object"
+}

Addedv2.8.1Jun 29, 2026

TDQS

B3.4/5.0

Behavior4/5

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

Annotations already supply readOnlyHint=false, idempotentHint=true, and destructiveHint=false. The description adds real behavioral context beyond them: notifications require a second, separate MCP resource subscription in addition to the Firebird listener, which an agent would otherwise miss.

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?

One compact sentence with the core action front-loaded and the prerequisite trailing after a semicolon. No wasted text, though the semicolon clause is slightly compressed.

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?

An output schema exists so return values need no explanation, and the dual-subscription note is a useful addition. Still missing is how to discover valid event names and how to later undo the subscription via unsubscribe_from_event, leaving the agent to infer the full workflow.

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

Parameters2/5

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

There is one parameter (eventName) with 0% schema description coverage, and the description says nothing about it—neither format, source of valid values, nor constraints. With a single required param the description had an easy opportunity to add a pointer to list_available_events and did not.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource: 'Register a Firebird POST_EVENT listener'. This clearly separates it from unsubscribe_from_event and list_available_events. It is not explicitly differentiated from siblings in prose, keeping it just short of a 5.

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?

It implies usage by naming a prerequisite ('MCP resource subscription is also required for notifications'), which is more than nothing. However, it never says when to subscribe vs. when to unsubscribe, nor points to list_available_events for valid event names.

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