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

Annotations declare a non-read-only, non-idempotent, non-destructive mutation; the description adds a genuinely useful server-side behavior note (Nilyo recomputes authorized account_ids). It does not say whether omitting a field leaves it unchanged or clears it, which matters given idempotentHint=false, so it stops short of full disclosure.

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 tightly packed sentences with the core action and field list front-loaded, followed by the workflow example and the server-side behavior note. No filler or repetition.

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?

For a 9-parameter mutation with no output schema and mixed schema coverage, the description is adequate but incomplete: it omits what an update returns, how unspecified fields are treated, and the meaning of enabled/runtime/auto_include_new_accounts. The presence of rich field descriptions in the schema offsets this only partially.

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 coverage is only 56% across 9 parameters, so the description must carry more weight, and it names only URL, events and provider/account selection, leaving enabled, runtime, auto_include_new_accounts and partial-update semantics unexplained. The value it does add on events/account_ids is already largely present in the schema field descriptions.

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 (Update) plus the resource (webhook destination) and enumerates the mutable fields (URL, events, provider/account selection). The n8n chain wording implicitly separates it from webhook_create_destination and webhook_get_destination, though no sibling is named outright, which keeps it 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.

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

Gives a concrete when-to-use scenario: create with a Test URL, receive a mock event, then update the same destination to a Production URL. That is clear usage context, but there is no explicit when-not-to-use (e.g. use webhook_create_destination for a new endpoint, webhook_test_destination to fire a test) and no prerequisite guidance.

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