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

Annotations already declare readOnly/idempotent/non-destructive, yet the description still adds real behavioral context: required role, key-scope constraint, and the 403 refusal for unclaimed sandbox workspaces. It also discloses that a signing secret (whsec_...) is returned and explains its purpose in verifying the x-lastprice-signature header, which is exactly the kind of sensitive-return detail annotations cannot convey.

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, front-loaded with what is listed and what comes back, then prerequisites. The parenthetical about the signature header is compact and adds genuine value rather than padding, so every sentence earns its place.

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?

There is no output schema, so the description carries the return-value burden itself and does so by naming each returned field. Combined with auth requirements and the 403 edge case, an agent has everything it needs to call this correctly and interpret the result.

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 tool takes zero parameters, so there is nothing to disambiguate; the baseline of 4 applies. The description correctly refrains from inventing parameter behavior and instead spends its words on return contents and preconditions.

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 and resource ('List your workspace's outbound webhook endpoints') and enumerates exactly what each entry contains (id, url, events, status, signing secret). The mention of endpoint configuration rather than delivery attempts implicitly separates it from the sibling list_webhook_deliveries, so an agent can pick correctly without opening a schema.

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 concrete preconditions for calling: owner/admin role, a key with no scope limits or a person's sign-in, and a claimed workspace with an explicit 403 outcome for sandbox keys from self-registration. It does not name alternative tools (e.g. list_webhook_deliveries when the agent actually wants delivery history), which keeps it out of the top band.

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