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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds the 3-tier cap and the default rate programme, which is useful domain context. However, with no output schema present, it gives no indication of what the simulation returns (per-tier amounts, totals, rounding), leaving a real behavioral gap.

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 Vietnamese and English sentences are essentially verbatim translations of one another, so roughly half the text is redundant token-for-token. It is front-loaded and free of hedging, but the duplication is real waste.

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?

For a small read-only computation tool with 2 fully documented parameters, little is needed. Still, the absence of an output schema means the description should say what a simulation result looks like, and it does not; nor does it note whether rates beyond 3 tiers are truncated.

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 both parameters (order_value in đồng, rates array defaulting to [20, 8, 5]) are already documented in the schema. The description only restates the default rates rather than adding constraints or interpretation beyond them, so the baseline 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: simulating referral commission on an order, capped at 3 tiers, with default program rates 20/8/5%. An agent can tell this computes multi-tier referral payouts. It does not, however, contrast itself with plausible siblings like build_quote or calculate_selling_price, so a 4 rather than a 5.

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?

There is no explicit when-to-use guidance, no mention of preconditions (e.g. whether an order must exist or whether this is purely hypothetical), and no routing to or away from sibling tools. Usage is only implied by the verb 'Mô phỏng / Simulate'.

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