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

No annotations are supplied, so the description carries the full burden. It never states that this is a mutating/persisting operation, whether drafts expire, what happens if the same session_id is reused, or what authorization the 'scoped' qualifier implies; the session_id note merely restates the schema.

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 short sentences with the core action first and the prerequisite second; nothing is redundant. The phrase 'for a scoped, agent-orderable service' is somewhat vague filler that could be replaced with concrete 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?

For a five-parameter creation tool with a nested object, no annotations, and no output schema, the description should explain draft lifecycle, relation to order.draft/checkout, and what a successful call yields. Neither the meaning of 'cart draft' nor the next step in the flow is covered.

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 parameters are already well documented, including quantity clamping, variant_key defaults, and service_configuration's nested fields. The description adds essentially nothing beyond the schema except the phrase 'caller-managed', which the schema already conveys.

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 description states a specific verb and resource (create a cart draft) and adds that the target is a scoped, agent-orderable service. It does not distinguish this from sibling tools like order.draft or quote.request, so an agent cannot tell from the text alone which draft mechanism to pick.

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?

It gives one prerequisite (caller-managed session_id), which is useful, but offers no when-to-use guidance against order.draft, quote.request, or availability.check, and no when-not-to-use conditions. Usage is only implied by the 'cart draft' framing.

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