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

Goes well beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false): explains that events are delivered externally to active receivers, that there is no immediate test send, that the one-time secret must be stored securely and not repeated, and that retries must reuse the identical body and idempotencyKey. These are the exact operational details an agent cannot infer from structured fields.

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?

Front-loads the core action and event scope, then layers prerequisites and safety notes. Dense but nearly every sentence carries actionable information; only the secret-handling sentence is slightly advisory rather than definitional.

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?

With no output schema, the description usefully notes that a one-time secret is returned and how to handle it, and it covers permissions, limits, and retry behavior for this mutating tool. It stops short of describing the full response shape or error behavior, but is sufficient for correct invocation.

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 33% — workspaceId and idempotencyKey are documented in the schema, while url, name, and isActive are not. The description compensates partially by implying the event values and the URL safety/approval requirement, but says nothing about name length or the isActive flag, so it does not fully close the coverage gap.

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 (Create), resource (Workspace subscription/webhook), and event scope (post.published/post.failed). An agent can immediately distinguish this from company_update_webhook, company_delete_webhook, and company_list_webhooks by the creation action and the event set.

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 clear preconditions: settings permission required, an approved public HTTP(S) receiver, backend destination-safety validation, and a 10-subscription cap. It does not explicitly route to a sibling for modifying or listing existing subscriptions, so the when-not/alternatives guidance is implied rather than stated.

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