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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description goes beyond them with the payment model ($0.002 USDC per successful call via x402 on Base/Solana/Arc) and the important detail that failed calls are not charged. It does not state rate limits or data freshness/latency, which would be the remaining behavioral gaps.

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 what the tool returns, followed by filtering behavior, scope restriction, and pricing. Every clause carries information an agent needs; nothing is redundant with the name or schema.

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?

An output schema exists, so return-value detail is unnecessary, and the description covers scope, filtering defaults, and cost. It stops short of handling edge cases such as a symbol with no matching Aave reserve or how the frozen/paused flags interact with a queried symbol.

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% and there is only one optional parameter, so the schema already documents 'symbol' with examples. The description restates the default behavior (first 20 reserves) but adds no semantics about unknown symbols or case sensitivity, 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?

Names the specific protocol, version, and market ('Aave v3 Ethereum main-market reserves') and enumerates the exact metrics returned (APY, utilization, LTV, liquidation threshold, caps, frozen/paused flags, liquidity). An agent can distinguish this from crypto_compound_market_stats or crypto_defillama_tvl_oracle immediately.

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?

States the two invocation modes clearly: filter by symbol, or default to the first 20 reserves, plus the hard scope limit 'Ethereum main market only.' It does not name a sibling alternative for other chains or protocols, which keeps it 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.