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

Annotations already mark readOnly, idempotent, and non-destructive, and the description reinforces this with concrete language ('creates no order and moves no funds'). It adds valuable behavior beyond annotations: cached quotes up to two hours for floating rates only, live quotes otherwise, and the fact that no account/email/ID is needed.

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?

The description is front-loaded with the core purpose and return value, then covers behavioral caveats, read-only safety, and prerequisites. Every sentence contributes meaningful information, and it remains compact despite covering several non-obvious behaviors.

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?

Given the output schema and annotations, the description is complete: it explains what is returned, when stale quotes are reused, that the operation is safe, how to source coin IDs, and that no auth is required. An agent has everything needed to invoke the tool correctly and interpret its behavior.

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%, so the baseline is 3. The description repeats the coin-id relationship with search_coins and examples already present in the schema, but adds little genuinely new parameter-level meaning. The rateType parameter is covered well in the schema, so no penalty is needed, but the description does not elevate it above baseline.

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 opens with a specific verb and resource: 'Estimate a crypto-to-crypto swap' on HiddenSwap. It clearly separates this from siblings like get_order_status, get_pair_info, and search_coins by emphasizing that it returns a quote with fees, rate, limits, payout fee, duration, and a prefilled 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?

The description gives clear context for when to call the tool: when an estimate is needed, and it explicitly routes users to search_coins for valid coin IDs. It does not explicitly contrast against get_order_status or get_pair_info, but the purpose and prerequisite are clear enough for an agent choosing among siblings.

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