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

Beyond readOnlyHint/openWorldHint, the description discloses genuinely useful behavior: it lists knowns vs 'Unknowns listed', states 'Figures, not advice', and explicitly says 'SwapEazi never holds, creates or moves liquidity'. It also discloses output gating by caller tier ('Free callers see Route A, Route B; a router key shows venue names'), which the annotations do not cover. No pagination/size-limit behavior is mentioned, 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?

The key claim is front-loaded in the first sentence, which is good. After that the text becomes a dense semicolon-chained enumeration that mixes inputs, outputs and disclaimers in one breath, and phrases like 'Being measured with the reason' are awkward enough to slow parsing.

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 7 parameters, a nested object and no output schema, the description carries the burden of describing returns and does so concretely: venue types, depth evidence, measured slippage and landing cost, Rate Receipt, largest supported size, and unknown handling. Only the tier-gating result (Route A/Route B redaction) and stopping conditions for large sizes are left partially implicit.

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 and the schema already carries pair/from/to/amount semantics. The description does add meaning for the nested prefunding object (idle fiat prefunding and stablecoin reserves, cost to enter and exit at that size, peg/exit depth, past official-rate move), which helps, but it never mentions access_key or amount_currency and adds nothing on their interaction.

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 opening sentence states a specific verb and outcome ('Shows where a payment of this size can be filled, and at what cost') and the rest enumerates exactly what is returned per venue type. An agent can tell this is a liquidity-depth/slippage mapping tool, though it never names the closest siblings (check_provider_liquidity, onchain_liquidity, assess_route) to sharpen the boundary.

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?

It states the required inputs (a currency pair and ticket size) and that prefunding is an optional add-on, which implies when the tool applies. But there is no explicit when-to-use/when-not-to-use guidance and no routing to alternatives, so the agent must infer the choice from sibling names alone. 'Same as GET/POST /api/v1/liquidity' is an API mapping, not usage guidance.

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