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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuine behavioral context beyond that: eligibility depends on live status, 'earn' appearing in venue_allowlist, and certification — details an agent cannot get from structured fields and that gate any subsequent action.

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?

It is front-loaded and dense, but the semicolon-and-em-dash chain ('rates, fees, lockups and validators; whether you can enter (live, ...); your balances...') reads as three concatenated topics rather than a structured statement. The parenthetical 'HLP (Hyperliquid's market-making vault)' earns its place; the rest could be tightened.

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 no parameters and no output schema, the description must convey what comes back, and it does list the categories of returned data plus the eligibility gate. Minor gap: it does not say whether balances and positions are always returned or only when Earn positions exist.

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?

The tool takes zero parameters, so the schema carries nothing to explain and the baseline is 4. There is no scope/filter vocabulary an agent could get wrong, and the description correctly treats it as a parameterless snapshot call.

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 names a specific resource set (HLP vault, HYPE staking, USDC lending) and the exact data returned (rates, fees, lockups, validators, eligibility, balances, positions). It is clearly a read/report tool, distinguishable from write siblings like earn_hlp_deposit or stake_hype, though it never explicitly names those alternatives.

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 gives one concrete precondition — 'Everything runs from your trading wallet (create_trading_wallet first)' — and implies the eligibility check is a pre-entry step. But it never states when to call this versus the deposit/withdraw siblings, so routing is left to inference.

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