mailbox-mcp

update_webhook_endpoint

DestructiveIdempotent

Modify a webhook endpoint’s URL, event types, keyword rules, name, or active status using expected revision to prevent concurrent edits.

Instructions

Update name, URL, events, keyword rules or active/paused status with expected_revision. Do not redirect notifications without the operator's authorization. Agent/environment scope cannot be changed. Requires webhook.manage. Uses the same bounded control plane and tenant/agent/Live-Sandbox authorization as /api/v1/webhooks/endpoints. Reuse the exact idempotency_key and input after an uncertain mutation. Webhook docs: https://mailbox.bot/docs/webhooks.

Input Schema

Name	Required	Description
`url`	No	Public HTTPS URL on port 443 (no credentials, fragment or private host) that receives the signed POSTs. Set or change it only on the operator's explicit instruction. Omit to keep the current value.
`name`	No	Label shown in the dashboard and delivery log. Omit to keep the current value.
`rules`	No	Up to 10 keyword rules, each with a unique id: source (envelope, letter for the contents, or any), match (any or all), 1–20 terms and optional exclude_terms. inbound.keywords_matched fires when a rule matches. Omit to keep the current value.
`status`	No	active or paused. Omit to keep the current value.
`endpoint_id`	Yes	Webhook endpoint id (UUID) from list_webhook_endpoints.
`event_types`	No	Events to deliver (1–32, unique). Inbound mail: inbound.received, inbound.action.requested, inbound.action.completed, inbound.pages_ready, inbound.keywords_matched. Outbound mail: mail.pending_approval, mail.submitted, mail.ready, mail.mailed, mail.delivered, mail.failed, mail.cancelled. Batches: batch.submitted, batch.completed, batch.partially_completed, batch.failed, batch.cancelled. Omit to keep the current value.
`idempotency_key`	Yes	A new UUID for this one intent; reuse it only to retry the identical request.
`expected_revision`	Yes	The endpoint's current revision from list_webhook_endpoints; a stale revision is refused so concurrent edits are never overwritten.

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed5 schema fields changedv1.0.4Oct 26, 2026

changedInput schema / properties / event_types / description

Previous value: -"Events to deliver (1–16, unique): inbound.received, inbound.action.requested, inbound.action.completed, inbound.pages_ready, inbound.keywords_matched. Omit to keep the current value."New value: +"Events to deliver (1–32, unique). Inbound mail: inbound.received, inbound.action.requested, inbound.action.completed, inbound.pages_ready, inbound.keywords_matched. Outbound mail: mail.pending_approval, mail.submitted, mail.ready, mail.mailed, mail.delivered, mail.failed, mail.cancelled. Batches: batch.submitted, batch.completed, batch.partially_completed, batch.failed, batch.cancelled. Omit to keep the current value."

changedInput schema / properties / event_types / items / enum

Previous value: -[
-  "inbound.received",
-  "inbound.action.requested",
-  "inbound.action.completed",
-  "inbound.pages_ready",
-  "inbound.keywords_matched"
-]New value: +[
+  "inbound.received",
+  "inbound.action.requested",
+  "inbound.action.completed",
+  "inbound.pages_ready",
+  "inbound.keywords_matched",
+  "mail.pending_approval",
+  "mail.submitted",
+  "mail.ready",
+  "mail.mailed",
+  "mail.delivered",
+  "mail.failed",
+  "mail.cancelled",
+  "batch.submitted",
+  "batch.completed",
+  "batch.partially_completed",
+  "batch.failed",
+  "batch.cancelled"
+]

changedInput schema / properties / event_types / maxItems
```
Previous value: -16New value: +32
```

changedOutput schema / properties / result / properties / endpoint / properties / event_types / items / enum

Previous value: -[
-  "inbound.received",
-  "inbound.action.requested",
-  "inbound.action.completed",
-  "inbound.pages_ready",
-  "inbound.keywords_matched"
-]New value: +[
+  "inbound.received",
+  "inbound.action.requested",
+  "inbound.action.completed",
+  "inbound.pages_ready",
+  "inbound.keywords_matched",
+  "mail.pending_approval",
+  "mail.submitted",
+  "mail.ready",
+  "mail.mailed",
+  "mail.delivered",
+  "mail.failed",
+  "mail.cancelled",
+  "batch.submitted",
+  "batch.completed",
+  "batch.partially_completed",
+  "batch.failed",
+  "batch.cancelled"
+]

changedOutput schema / properties / result / properties / endpoint / properties / event_types / maxItems
```
Previous value: -16New value: +32
```

Addedv1.0.3Oct 12, 2026

TDQS

A4.1/5.0

Behavior5/5

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

Beyond the annotations (destructive, idempotent, open-world), it discloses optimistic concurrency control (stale revision refused, concurrent edits never overwritten), the authorization model (tenant/agent/Live-Sandbox, webhook.manage), the immutable scope fields, and the retry protocol after an uncertain mutation. These are exactly the mutation risks an agent needs surfaced.

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?

Purpose is front-loaded and nearly every sentence carries a distinct constraint (auth, scope immutability, idempotency, docs). The 'same bounded control plane ... as /api/v1/webhooks/endpoints' sentence is referential filler, and the important 'do not redirect' warning is buried mid-paragraph rather than placed next to the URL field.

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?

For a destructive mutation with rich annotations, a full output schema, and 100%-covered parameters, the description supplies everything else an agent needs: permissions, concurrency expectations, retry semantics, immutable fields, and a docs URL. Nothing material for correct invocation is missing.

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% and the schema itself already documents per-field semantics, enums, limits, and omit-to-keep behavior, so the baseline is 3. The description only restates the field list and ties expected_revision to the update, adding little the schema doesn't already say.

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?

The opening sentence names the resource (webhook endpoint) and enumerates the mutable fields plus the required expected_revision, so the operation is unmistakable. However it does not distinguish itself from the sibling tool `update_webhook`, which an agent must choose between; the 'endpoint' suffix is the only hint.

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?

It states real preconditions and exclusions: requires webhook.manage, agent/environment scope cannot be changed, and notifications must not be retargeted without operator authorization. It also tells the agent to reuse the identical idempotency_key and input on retry. It stops short of routing the agent versus `update_webhook` or `create_webhook_endpoint`.

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

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