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

No annotations exist, so the description carries the full burden and does most of it: it states the tool is read-only ('nothing is sent'), discloses that deposits mint shares and earn immediately, that withdrawals depend on unborrowed liquidity, and that the supply APY is approximate and net of a 10% performance fee. Missing are auth/rate-limit behavior and any indication of how the APY approximation is derived.

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?

One dense but well-ordered paragraph: side and instrument first, then enumerated return contents, then behavioral caveats (fee, liquidity, read-only, eligibility). Every clause carries information an agent would otherwise have to guess.

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 output schema and no annotations, the description usefully enumerates what comes back (vault, total assets, cap and room, utilization, borrow rate, approximate APY, my position), which is the right burden to shoulder. Minor gap: no units or formatting for the numeric fields and no pagination/refresh semantics for 'live market' data.

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 single `account` parameter has 0% schema description coverage, so the description must compensate — and it does, defining `my` as 'the account's vault shares, their USDG value and its wallet USDG', which tells the agent the parameter is the account whose position is reported. It does not specify the expected address/identifier format.

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?

Specific verb-and-resource framing: 'Share Lending, LEND side' plus a concrete scope list (vault, total assets, cap and room, utilization, borrow rate, supply APY, my position). It clearly separates the LEND side from the borrow_* siblings, but never distinguishes itself from the closely named vault_status sibling, so an agent could still hesitate between those two.

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?

Usage context is clear — it is a read-only status read, and the note that 'a withdrawal needs unborrowed liquidity' signals when the cap/room and utilization fields matter. It stops short of explicitly routing the agent (e.g., 'to preview a deposit use lend_deposit_quote'), and the 'Not for US persons' line is a eligibility caveat rather than a when-to-use rule.

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