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

With annotations only covering the mutation/safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), the description supplies the economically important behavior: a 0.55% entry fee collected after the deposit lands, a 4-day lockup, and exposure-cap accounting. It also discloses the two-signer authorization model (OWNER P-256 over payload_b64 vs. trading key over EIP-712 typed_data), the verification step, and the 5-minute submission window — none of which is inferable from annotations or schema.

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?

Purpose, cost, and constraints are front-loaded, and every clause carries real information — fee, lockup, cap, signer mapping, timeout. The heavy nested parenthetical around payload_b64 verification makes the second half dense and harder to parse than a short bulleted breakdown would be.

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 non-idempotent, open-world mutation that initiates a multi-step signing flow, the description covers cost, minimum, lockup, cap impact, signer identification, payload verification, and the submission deadline. With no output schema, it also names the return shape (operation_id + signatures_needed[]) so the agent knows what to do next.

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?

There is a single parameter and schema description coverage is 100%; the schema already states the $5.03 minimum and that the 0.55% fee is taken from the amount. The description repeats those facts rather than adding new semantics such as rounding or unit conventions, so 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?

The description opens with a specific verb, asset, and destination: "Deposit USDC from your trading wallet into HLP." That phrasing is precise enough to separate it from earn_usdc_deposit, earn_hlp_withdraw, and earn_usdc_withdraw without opening any schema.

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 the full usage sequence after the call: sign each entry in signatures_needed[] with the named signer, verify the payload, then call submit_operation within 5 minutes. It also states eligibility constraints (min $5.03, counts toward the exposure cap) that gate whether the call is valid. It never explicitly contrasts HLP with the USDC earn sibling, so it stops short of a 5.

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