register_webhook

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

With zero annotations provided, the description carries full burden and succeeds: it discloses encryption-at-rest of the HMAC secret with keyring details, the delivery headers (X-Relay-Delivery-ID, X-Relay-Idempotency-Key, X-Relay-Signature), SSRF validation against cloud-metadata/private-IP blocklist, the full event list, the return envelope shape, and all error codes with causes. This is exemplary behavioral disclosure for a tool with no annotations.

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?

Well-structured with labeled sub-sections (When to use, Behavior, Events, Returns, Errors) that front-load the purpose and usage before deep behavioral detail. Every sentence earns its place, though the length is substantial — justified given the tool's complexity and zero annotations, but slightly more than strictly minimal.

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 5-param, 2-required tool with no output schema and no annotations, the description is remarkably complete: it covers the output envelope, all error modes, security behaviors, event taxonomy, idempotency headers, and alternative tools. There are no significant information gaps an agent would need to guess at.

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 100%, so parameters are documented in schema. The description adds meaningful context beyond the schema: the filter's mechanism ('narrows by sender/recipient') amplifies the schema's agent-name description, and the 'optional * wildcard' behavior is integrated. The secret's return-field interplay (has_secret) is disclosed. Minor credit withheld only because most param semantics already live in the schema, which the description appropriately acknowledges.

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?

Description states a specific verb+resource ('Subscribe an HTTP endpoint to relay events') that clearly differentiates from siblings like list_webhooks and delete_webhook, and identifies the subscribed event types. It enumerates the full event taxonomy and filter capability, leaving no ambiguity about what the tool does.

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?

Explicit 'When to use' section names reactive integration scenarios (Slack notifier, audit pipeline) and contrasts against alternatives: 'For polling-style observation prefer get_standup or peek_inbox_version' and notes /dashboard already consumes live events. This gives clear when-to and when-not-to guidance.

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