Stake into an Arbitrage product

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

Annotations already flag readOnlyHint=false, destructiveHint=true, idempotentHint=false, so the mutation risk is covered structurally. The description adds the key auth requirement (`Earn` permission) plus an example response showing a txid, which is useful context beyond the annotations.

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?

Front-loads the verb and permission/weight metadata, then validation, then examples. Slightly padded by a response example that isn't strictly needed, but every section is scannable and earns its place.

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 3-param mutation tool with no output schema, it covers permission, validation, and a sample request/response. The main missing piece is what happens on failure or whether the stake can be withdrawn (though the unstake sibling implies reversibility).

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 coverage is 100%, so baseline is 3, but the description restates the enum constraint, the decimal-amount requirement, and the source-of-truth for productId, and adds a concrete example body showing amount as a string. It mostly mirrors the schema, keeping it just 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?

States a specific verb+resource ('Stake into an Arbitrage product') and explicitly scopes it as subscribing to a Term Arbitrage product. The validation note tying productId to `GET /api/v1/earn/arbitrage/fetchProducts` also distinguishes it from siblings like pionex_earn_arbitrage_un_stake and fetch_products.

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 clear preconditions: requires `Earn` permission, productId must come from the fetchProducts list, and coin is limited to USDT/USDC. It doesn't state explicit when-not conditions or naming the unstake sibling as the inverse alternative, but the context is strong.

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