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

Annotations already declare readOnly, idempotent, non-destructive, closed-world. The description adds real value beyond them: 'Deterministic template with open questions' tells the agent the output is a reusable template that may surface unresolved items rather than a final decision. It does not discuss output format, but an output schema exists.

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?

Two tight sentences, front-loaded with the core action and scope; the template/determinism note is placed at the end as a secondary qualifier. No wasted text.

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?

Behavioral context is adequate and an output schema covers returns, but with 6 required parameters and zero schema descriptions, the description leaves the agent without guidance on what to supply for producer, consumers, payloadFields, or the enum choices.

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 0% and the description adds no per-parameter meaning. It mentions 'named business event' (loosely eventName) and ordering, but does not explain producer, consumers, payloadFields structure, or the ordering/deliveryGuarantee enums, leaving the agent dependent on bare schema field names.

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?

Specific verb ('Design') and resource ('event contract') plus an enumerated scope: envelope fields, schema evolution, idempotency, ordering, DLQ, replay. An agent can distinguish it from delete/update style tools, though it does not explicitly contrast itself with adjacent design tools like retry_policy or integration_config.

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 phrase 'for a named business event' and the listed decision areas imply when it applies, but there is no explicit when-to-use/when-not guidance and no named alternative for overlapping design tasks (e.g., sequence_diagram, integration_config).

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