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

Annotations already declare readOnly=false, openWorld=true, idempotent=false and destructive=false, so the description is freed from the safety story. It still adds real behavioral context — that delivery is asynchronous push, per-event, at the moment events occur. It omits delivery failure/retry behavior, signature verification, and whether re-registering the same URL creates duplicates, which matter for a non-idempotent webhook subscription.

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 tight sentences, front-loaded with what gets created and what happens next. No filler and no repetition of the title.

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?

An output schema exists, so return values need not be described, and both required params are covered. For a webhook-creation tool, though, an agent still lacks guidance on verifying the payload source and on avoiding duplicate subscriptions (e.g., check list_hooks first).

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 the baseline is 3, but the description earns extra credit by enumerating concrete event_type values (contact_created, form_submitted, appointment_booked) that the schema has no enum for. It does not add format or validation detail for target_url beyond what the schema states.

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 (register a webhook URL) plus the concrete mechanism (MightyAutomation POSTs matching events to it). It is clearly distinct from sibling list_hooks/list_events by describing push vs. pull delivery.

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?

Explicitly names the alternative ('instead of polling list_events') and gives the selection condition (real-time notifications vs. polling). It also tells the agent which value to use for all events ("*") versus a specific type.

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