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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so safety is covered. The description adds context beyond that: no key is required to call it, and it returns, for each capability, the tool and action to use next, which tells the agent this is a discovery/router call rather than a data read.

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?

The opening sentence is front-loaded and clear about scope. The trailing "Send action and its arguments. Without action it runs seller" repeats the schema's documented default and is wasted space, and the phrasing "the ways to offer, to be found and to be paid" is a loose paraphrase of the actual enum values.

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?

With no output schema, the description does the necessary work by saying the result lists each capability alongside the tool and action it maps to. The only gap is that the returned shape (grouped structure, size) is not hinted at, but an agent can call it correctly from what is given.

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% and both parameters have enums with defaults already documented. The description restates 'group narrows it' and 'without action it runs seller', matching the schema without adding format or interaction details beyond it. 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 specific verb and resource: reading seller capabilities, enumerated as ways to offer, be found, and be paid, returned with the tool and action for each. It does not name any sibling, but the enumerated scope makes what it returns distinct from the marketplace/feedback/start tools.

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 first call of a seller agent" gives one clear entry-point cue, which is useful. However there is no explicit differentiation from the similarly named commercebook_start or commercebook_account_start siblings, so an agent must infer which of the three onboarding-looking tools to call first.

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