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

This is the description's strongest contribution: it discloses that invoking the tool mutates nothing, that it returns a preview plus a confirmation link, and that only the merchant on that page can apply the change. None of that is derivable from the annotations, and it materially changes how an agent should sequence its calls. The tension with readOnlyHint=false is resolved by the text itself — the operation is a proposal, not a direct write.

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?

Four short sentences, front-loaded with the purpose and the no-op behavior, with no padding. The money-units sentence earns no place here because the schema contains no monetary field, which is the only real deduction.

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 correctly takes on the burden of describing the return value (a preview of changes plus a confirmation link), which is exactly the missing piece an agent needs. The single parameter is fully documented in the schema, so little is left unspecified beyond error handling.

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% and the nested feed object documents name, slug, and collection semantics (including the slug-preservation warning) far better than the description does, so the baseline of 3 applies. The only parameter-relevant sentence in the description — "Money is integer minor units (cents)" — refers to no field in this schema and reads as noise from another tool.

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 names a specific verb and resource ("Set the shop's shopping feeds") and immediately clarifies that the call is a preview rather than a commit, which sharpens the purpose considerably. It does not, however, contrast itself with the sibling shopping_feeds_list, so an agent must infer the read/write split from the names alone.

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 description explains the confirmation workflow (preview, confirmation link, merchant approves) but never states when to reach for this tool versus shopping_feeds_list or how to recover from an unwanted proposal. Usage is implied by the tool name rather than spelled out, which is adequate but leaves the routing decision to the agent.

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