HTML/CSS to Image API

Update a Webhook

update_webhook

Destructive

Replaces a webhook's configuration. Omitted parameters are removed; resend secret values or keep them with retain_value: true, except when the URL changes. Changing the URL, parameters, or signing setting, or enabling the webhook, requires read access to every subscribed event and sends a webhook_test delivery, identified by test_event_id in the result. Disabling, renaming, or removing subscriptions only requires webhook management access. Fails with a conflict if the webhook changed concurrently; get it again before retrying.

Input Schema

Name	Required	Description	Default
`id`	Yes	ID of the webhook to update.
`content`	Yes	Complete replacement webhook configuration.

Output Schema

Name	Required	Description
`item`	No	Operation result. Check success before using this value.
`error`	No	Error details when the operation failed; null on success.
`success`	No	Whether the operation succeeded. If false, inspect error before retrying.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedNov 3, 2026

changedInput schema / properties / content / properties / signing_enabled / description

Previous value: -"Whether to sign deliveries with this webhook's signing secret. The secret is generated when the webhook is created and can be copied from the dashboard. Defaults to false."New value: +"Whether to sign deliveries with this webhook's signing secret. The secret is generated when the webhook is created, returned only in the REST API create response, and can also be copied from the dashboard. Defaults to false."

addedOutput schema / properties / item / properties / signing_secret

Added value: +{
+  "description": "Signing secret for verifying deliveries. Returned only in the REST API create response, even when signing is disabled. Store it securely; updates, reads, lists, and MCP responses omit this field.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

AddedOct 29, 2026

TDQS

A4.6/5.0

Behavior5/5

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

Annotations already flag destructive, non-idempotent, open-world behavior, but the description adds real substance beyond them: omitted parameters are deleted, secret values must be resent unless retain_value is used (and cannot be kept when the URL changes), mutating calls emit a webhook_test delivery identified by test_event_id, and concurrent modification fails with a conflict. These are the non-obvious side effects an agent would otherwise discover only by breaking a webhook.

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?

Five dense sentences, front-loaded with the replacement semantics that matter most, and no filler. The permissions sentence is long and packs several conditions together, mildly reducing scannability, but every clause carries information.

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, nested-object mutation with 100% schema coverage and an output schema, the description covers the remaining agent-relevant gaps: permissions per change class, secret retention rules, the test-delivery side effect, and the conflict/retry path. Nothing needed to call this safely is missing.

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

Parameters4/5

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

Schema coverage is 100%, so baseline is 3; the description earns upward credit by summarizing cross-parameter rules — resend secret values versus retain_value: true, and the URL-change exception that invalidates retention — in a single place rather than leaving the agent to synthesize nested field descriptions. It still defers most detail (limits, reserved header names) to the schema.

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?

Opens with a precise verb and resource — 'Replaces a webhook's configuration' — and immediately qualifies it with replacement semantics ('Omitted parameters are removed'), which distinguishes it from create_webhook and from a partial-patch tool. An agent can identify the operation without touching the 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?

Gives concrete decision conditions: which field changes require read access to every subscribed event and trigger a webhook_test delivery, versus which changes only need webhook management access, plus retry guidance after a conflict. It does not name sibling tools (e.g. send_webhook_test_event, get_webhook) as alternatives, so it stops short of explicit routing.

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

All HTML/CSS to Image API tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.