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

With no annotations, the description carries the full burden and does well: it discloses paid pricing ($0.002 USDC), accepted payment chains (Base or Solana), no account/API key requirement, no charge on failure, and the upstream data source (DefiLlama). It omits response shape and any rate/limit behavior, which keeps 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?

Two dense sentences with the payment/access constraints front-loaded and zero filler. The telegraphic style ('Paid. Live DeFi yields...') is efficient, though it packs pricing and URL into the same breath as purpose.

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 zero-required-parameter read tool with no output schema, the description covers what the tool is, what it returns (metric list), what it costs, and how access works. A line on pagination or maximum rows returned would close the last gap.

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 100% with per-parameter descriptions for sort, limit and min_tvl_usd, so the schema does the explaining. The description adds no sorting, paging or default-value context beyond it, making 3 the correct 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?

The description names the resource precisely ('DeFi yields for upshift: its pools across chains') and enumerates the returned metrics (APY, TVL, 7d APY change). It doesn't explicitly contrast itself with chain-level or top-yield siblings, but the protocol scope in the name plus description makes the target unambiguous.

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?

There is no when-to-use or when-not-to-use guidance and no named alternative, despite a large family of near-identical siblings (buy_yields_chain_*, buy_yields_token_*, buy_yields_top). The agent must infer from the protocol name alone whether this or a chain/token tool is the right call.

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