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

With no annotations, the description carries the full load and does well: it discloses that the call is paid ($0.005 USDC on Base or Solana), that no account or API key is required, that failed calls are not charged, and that data originates from DefiLlama. It omits rate limits, latency, and what an error or empty result looks like, so it stops short of full behavioral coverage.

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 "Paid." and then the resource definition, followed by pricing, access terms, billing policy, and source URL in a tight telegraphic sequence. Every clause carries a distinct operational fact and nothing is redundant.

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?

For a three-optional-parameter read tool with no output schema, the description covers cost, payment rails, auth, billing on failure, and the data source, and it names the returned metrics (APY, TVL). The only real gap is that it never sketches the shape of the rows returned or the protocols/chains involved.

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 sort, limit, and min_tvl_usd are already documented with defaults in the schema. The description adds nothing about them — no guidance on when to sort by apy versus tvl or how the default TVL floor affects results — so it sits at the baseline.

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?

"Where to earn yield on SUSDAI: live pools holding SUSDAI across protocols and chains, APY and TVL" names a concrete resource (yield pools for a specific token) and the exact payload fields. It is clearly distinguishable from the token-specific siblings by the SUSDAI subject, but it never contrasts itself with adjacent tools such as buy_yields_stablecoins or buy_yields_token_usdc.

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 is only implied: the agent can infer it should call this when it wants yield opportunities for SUSDAI, and the "live pools ... across protocols and chains" phrasing hints at breadth. There is no explicit when-to-use/when-not statement and no pointer to the sibling that covers a different token or the aggregate stablecoin view.

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