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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds value beyond them by disclosing the returned payload contents (fee tables, surcharge tiers, merge rules) even though no output schema exists.

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 sentences, front-loaded with the resource and its contents, then the usage note. The long enumerated clause is dense but every item listed is substantive; minor trim possible on the courier-name parenthetical.

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 carries the return-value burden and does so thoroughly by listing fee categories, surcharge structure, payment methods, and merge rules. Nothing an agent needs to decide or call correctly is missing.

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?

Zero parameters, so there is nothing to disambiguate and the baseline applies. The description correctly does not waste space on argument semantics.

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?

Specific verb + resource: it returns the shop's current shipping and payment options, and then enumerates exactly what is inside (courier base fees for MPL/GLS/Posta, COD tiered surcharges, payment methods, free order-merge rules). This clearly separates it from siblings like get_product_price, get_bank_details, and get_faq_answer.

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 final sentence gives clear usage context: extract exact fees and conditions from the returned JSON to build the answer, which tells the agent when to reach for it. It stops short of naming alternatives or exclusions (e.g. when to prefer get_faq_answer for policy questions), so it is not a full 5.

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