create_webhookCreate a webhook endpoint. Returns the endpoint plus a signing secret (shown once).
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | HTTPS URL that receives events | |
| events | No | Event types to deliver (all of them when omitted) |
| Name | Required | Description | Default |
|---|---|---|---|
| secret | Yes | Signing secret for verifying deliveries. Shown only once. | |
| webhook | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "secret": {
+ "description": "Signing secret for verifying deliveries. Shown only once.",
+ "type": "string"
+ },
+ "webhook": {
+ "properties": {
+ "created_at": {
+ "description": "ISO 8601",
+ "type": "string"
+ },
+ "enabled": {
+ "type": "boolean"
+ },
+ "events": {
+ "description": "Event types delivered",
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+ },
+ "id": {
+ "description": "Webhook id",
+ "type": "string"
+ },
+ "updated_at": {
+ "description": "ISO 8601",
+ "type": "string"
+ },
+ "url": {
+ "type": "string"
+ }
+ },
+ "required": [
+ "id",
+ "url"
+ ],
+ "type": "object"
+ }
+ },
+ "required": [
+ "webhook",
+ "secret"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the write/openWorld/non-destructive profile, lowering the bar. The description adds a genuinely useful behavioral fact beyond that: the signing secret is returned and shown only once. It omits auth requirements, rate limits, and duplicate-endpoint behavior, keeping it from a 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two short sentences, front-loaded with the core action and followed immediately by the key return-value caveat. No wasted words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With an output schema present and annotations covering the safety profile, the description needn't restate return structure. It still contributes the critical "shown once" secret semantics, which the schema would not convey. Complete enough for correct invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
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 url and the events list (including the "all of them when omitted" default). The description adds no parameter-level detail, making the baseline 3 correct.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource ("Create a webhook endpoint"), which naturally separates it from delete_webhook and list_webhooks. It stops short of explicitly naming a sibling or differentiating itself, so it lands just under a 5.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description offers no when-to-use guidance, no prerequisites, and no pointer to related tools such as send_test_webhook_event or list_webhooks. An agent gets no help deciding when this tool is the right call versus its siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.