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

Annotations already mark this read-only, non-destructive and closed-world, and the description adds substantial context on top: it does not contact the shop, reserve stock, create an account/cart/order, or charge money, and the customer completes price, shipping, login and payment on cigo.kr. The instruction 'Never report a completed purchase' directly guards the most likely agent error for this tool.

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?

Six sentences, each doing distinct work: purpose first, then required inputs, then scope constraint, then negative capability, then who completes the transaction, then the routing rule. No repetition of the title and no filler.

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?

There is no output schema, but the description explains what is produced ('only formats a link') and what the link implies for downstream steps, so an agent knows the return value and the handoff boundary. For a four-required-parameter, annotation-covered tool, nothing material 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?

Schema description coverage is 0%, so the description must carry the load, and it does: it maps the four required fields to 'vehicle model/generation, model year, quantity and shipping country' and constrains shipping_country to Korean domestic only. It stops short of format detail for model_name (Korean-market fitment identifiers are mentioned but not exemplified) and valid ranges for year/quantity.

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 concrete verb and artifact: 'Prepare a Cigo own-store checkout link' for a Carsafe filter purchase. It immediately distinguishes itself from siblings by scoping to own-store checkout for a specific product line, leaving search_carsafe, get_hvac_filter_info and submit_b2b_inquiry for other intents.

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 an explicit trigger ('after the customer asks to buy a Carsafe filter'), explicit prerequisites (collect vehicle model/generation, year, quantity, shipping country first), and explicit exclusions ('For HVAC, materials or overseas delivery, use an inquiry instead'). It also blocks a common misuse path with 'do not infer country from language.'

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