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

Goes well beyond the readOnly/destructive annotations: it explains that the call returns only a URL, creates no order or cart, takes no payment, and — critically — that 'Opening it starts a new cart and can replace an existing cart', a side effect the annotations cannot express. The PII warning adds further operational context an agent needs.

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-loads purpose, then behavior, then args in a scannable block — good ordering. Slightly redundant in places (the size/colour instruction appears both in prose and in the variant_id arg line), but with 0% schema coverage the Args block is necessary rather than padding.

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 six-parameter, no-output-schema tool it covers the return value (a URL), the side-effect profile, language constraints, and input prerequisites. It leaves minor gaps: link expiry, and error behavior when a variant_id does not match the product.

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%, so the description carries the full burden and does: store values (com=WooCommerce, org=Medusa), product_id vs variant_id distinction, quantity bound 1-10, per-store language lists, and handle defined as an org slug in the same language. This is meaning no agent could recover from the bare schema.

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 — 'Get a SIIL checkout link for one shopper-selected product and size/colour' — and scopes it to a single product/variant, which clearly separates it from the sibling search_products/get_product tools that supply IDs. An agent can tell what it produces (a URL) 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 concrete workflow preconditions: 'Ask for size/colour before selecting a variant', product_id must come from get_product or get_org_product, and 'Never request personal, address or card data in chat'. It routes to the sibling tools for input sourcing, though it never states a case where this tool is the wrong choice outright.

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