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

Annotations already declare the safety profile (mutation, non-destructive, non-idempotent, closed-world), so the bar is lower. The description adds a genuinely non-obvious behavior: 'Nilyo recomputes authorized account_ids server-side,' telling the agent the account selection may be adjusted server-side rather than used verbatim.

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?

Three sentences, purpose front-loaded, then workflow context, then a behavioral note. Each sentence carries information; no filler or repetition of the schema.

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?

No output schema, 9 params with only 56% description coverage, and a mutation tool whose partial-vs-full update semantics (what happens to unspecified fields) are never stated. The purpose and workflow are covered, but an agent still lacks enough to call this confidently in edge cases.

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?

The description names three updatable categories (URL, events, provider/account selection) mapping to request_url, events, and providers/account_ids, which helps scope the call. But schema coverage is only 56% and name, enabled, runtime, and auto_include_new_accounts get no mention, so the description does not fully compensate.

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), resource (webhook destination) and the fields affected (URL, events, provider/account selection), so an agent knows this is the mutation counterpart to webhook_create_destination. It stops short of naming a sibling as an alternative, but the update/create verb split plus the referenced n8n chain provides implicit differentiation.

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 'Common n8n chain: create with Test URL -> receive mock event -> update same destination to Production URL' gives concrete context for when to reach for this tool. No explicit when-not conditions or named alternatives are offered, but the workflow framing is clear usage context.

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