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

Annotations already cover readOnly=false, destructive=true, openWorld=true, and idempotent=false. The description adds genuinely useful non-obvious behavior beyond the annotations: 'Returns a webhook secret on first creation only' — an actionable disclosure (capture the secret at creation; don't expect it on update). It could add what exactly is overwritten/destroyed on update, but with annotations present the bar is lower and this clears it.

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 with no wasted words: purpose front-loaded first, the secret behavior second, and the API anchor third. Each sentence has clear function, and the most important operational caveat (secret only on first creation) surfaces early.

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 6-parameter mutation tool, the full schema and output schema carry most of the burden while the description covers the crucial behavior an agent can't derive from them: the one-time secret and the create-vs-update mode. Remaining gaps — exact overwrite semantics on update and required permissions — are not covered, but annotations and use of enrich schema reduce the need.

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 all six parameters are already well documented in the schema. The description adds only marginal semantic value ('URL + subscribed events' maps to webhook_url/events), which is insufficient to exceed the baseline of 3.

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?

The description uses a specific verb+resource ('Create or update a business outbound webhook') and scopes it to (URL + subscribed events), which an agent can act on directly. It does not explicitly name or contrast the webhook siblings (get_webhook, delete_webhook), but the create/update semantics make the distinction self-evident.

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 implies when to use the tool (whenever a webhook needs to be created or updated) but gives no explicit when-not or alternative guidance. The schema hint in the events parameter ("see get_webhook for the supported list") nudges toward the read sibling, but the description itself does not position this tool against get_webhook or delete_webhook.

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