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

No annotations are present, so the description carries the full burden, and it does so thoroughly. It discloses event matching rules, dot-hierarchical prefix matching, the ownership requirement, the one-time-only return of the signing secret, and the exact HMAC signature header format for verification.

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?

The description is dense but front-loaded: the main action comes first, followed by matching behavior, ownership, non-recoverable secret, and signature verification. Every sentence adds needed operational context, though the long first sentence includes some redundancy with the schema's parameter docs.

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?

Given the tool's complexity and the absence of annotations and an output schema, the description is largely complete. It covers invocation semantics, authentication requirements, the one-time secret, and verification details; only edge behaviors like duplicate registrations or error cases are left unspecified.

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 the baseline is 3 even without additional parameter explanation. The description does restate and slightly extend the prefix semantics by naming kv put, queue push, and topic publish as event sources, but it does not add materially new meaning beyond the schema's own parameter 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?

The opening phrase 'Register an outbound webhook target' names a specific verb and resource, and the description immediately specifies the triggering behavior and matching semantics. It clearly distinguishes this from sibling tools like list_webhook_targets and unregister_webhook_target.

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 gives clear context for when the tool is appropriate: it is for registering a webhook target that will receive POSTs on matching writes, and it states the ownership prerequisite. It does not explicitly call out alternatives or when-not-to-use cases, but the purpose is evident from the name and siblings.

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