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

Annotations already declare non-read, non-idempotent, non-destructive behavior, and the description adds substantive context beyond them: repeat calls with the same email create a second lead rather than updating (concretely explaining the non-idempotency), no invoice is created and nothing is reserved, and the return includes an intentRef plus a stated follow-up expectation.

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-loaded with the core action and the key distinctions (lead vs order, keyless vs keyed) packed efficiently. Minor flourishes like 'the journey's first ask' cost a little, but every sentence carries actionable information.

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?

No output schema exists, yet the description covers the return (intentRef, optional artworkRef linkage, follow-up expectation), auth requirements, and duplicate-call behavior. For a five-parameter write tool this is as complete as an agent needs to call it correctly.

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 schema already documents all five parameters including artworkRef linking and optional hints. The description adds only the framing that the email drives follow-up routing and that linking an artworkRef ties an earlier submission to the lead, which is marginal beyond the schema; baseline 3 applies.

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 concrete verb and resource: capture a contact email as a lead/intent through the public capture endpoint. It explicitly contrasts the intent with an order ('an intent is a lead, not an order') and names create_order as the separate keyed path, so an agent can distinguish it from siblings without opening the schema.

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 explicit when-to-use (kickoff of the journey, once per contact) and when-not (completing an order requires create_order with an API key), plus the 'no key needed' precondition. It even directs the agent to get_discovery for how to obtain the key, leaving nothing to inference.

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