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

Annotations already declare readOnly, idempotent, openWorld and non-destructive. The description adds valuable context beyond them: a $0.002 cost, 10-minute on-chain refresh cadence, base-yield-only scope, and result ordering. This is solid behavioral detail layered on top of the safety 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?

A single dense sentence that front-loads purpose, price and sort order, with no filler sentences. It is somewhat crammed with parenthetical lists, but every clause carries information.

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 compensates by naming the returned fields (supply/borrow APY, utilization, USD size), the sort order and refresh cadence. It is nearly complete for an agent to invoke and interpret results, though it could clarify parameter interactions (e.g. asset vs chain defaults).

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 80%, so the schema already documents asset, chain, limit, protocol and minTvlUsd. The description echoes example assets and chains but adds no syntax or semantics beyond what the schema provides. Baseline 3 applies when structured data does the heavy lifting.

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 precise resource (DeFi lending yields) with the exact metrics returned (supply/borrow APY, utilization, USD size), the protocols (Aave v3, Spark, Compound v3) and chains covered. No sibling tool overlaps this domain, so differentiation is inherent.

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 implies the use case (finding the best supply rate for major assets) and notes scope limits ('base yield only, no reward tokens'), but gives no explicit when-to-use/when-not guidance or alternatives. Usage is inferable but not stated.

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