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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds genuinely new behavioral facts: v4-only availability, per-item granularity the aggregate cannot provide, and the conditional presence of 'quotableAs' (absent when the item can enter neither route). Return shape and pagination are not covered, keeping it short of a 5.

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-loaded with the v4 constraint and the core differentiator, then the identifier-to-downstream-tool mapping. Dense but every clause carries routing or interpretation value; the single long sentence is slightly harder to scan than a split structure 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?

With no output schema, the description carries the return-value burden and does: principal, accrued interest, withdrawable amount per item, plus the meaning of positionItemId and quotableAs. It also explains where the required spokeId comes from. Nothing an agent needs to call or interpret it correctly is missing.

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 'side', 'user', 'spokeId' and 'version' are already documented, including the enum values. The description reinforces the spokeId provenance but largely restates what the schema says, 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/resource tuple — the individual supply or borrow items inside one v4 spoke — and explicitly contrasts it with the per-spoke aggregate returned by get_user_positions. An agent can distinguish it from the sibling 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?

Names the prerequisite call ('Get spokeId from get_user_positions'), the hard scope constraint (v4 only), and the downstream consumers (get_position_swap_quote's sellPosition, get_repay_with_supply_quote's debtPosition) selected via 'quotableAs'. It also states when an item cannot be used for either route.

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