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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so safety is covered. The description adds genuinely non-obvious behavior beyond that: the same link returns a checkout-style product page to a person but an x402 USDC payment challenge to an agent. It does not cover link lifetime or auth requirements, keeping it short of a 5.

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, zero preamble, with the core behavior front-loaded before the usage cue. The trailing enumeration 'chat, a social post, or a message' is mildly padded but still earns its place by naming concrete share surfaces.

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 only two fully documented parameters and no output schema, the description carries the right burden: it explains what the returned link does in both consumption modes. It leaves minor questions unanswered (link permanence, whether re-requesting returns an identical link), but nothing an agent needs to invoke it correctly.

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%, with both handle ('Seller swop.id, e.g. "travis.swop.id"') and sku ('Product sku/id from swop_get_store') documented, including the cross-reference to the sibling that produces the sku. The description adds no parameter-level meaning, so the baseline of 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 ('Get one link') and explains the dual behavior of the resulting artifact — a human-facing product page with a Buy button versus an x402 USDC payment challenge for agents. This is more specific than most siblings, though it never explicitly distinguishes itself from swop_add_link, swop_remove_link, or swop_pay_x402_link.

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?

Provides concrete usage context: 'Use this to share a product in chat, a social post, or a message.' It gives a clear when-to-use but names no alternatives or exclusions, so the agent must infer this is the retrieval/share path rather than the creation path (swop_add_link) or the pay path (swop_pay_x402_link).

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