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 that the call is paid ($0.01 USDC on Base or Solana), requires no account or API key, and that failed calls are not charged. It does not cover rate limits, response shape, or pagination behavior, but the cost/authorization profile is unusually well specified.

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-loads the paid flag, then purpose, then pricing/payment rails, then the endpoint URL. Every sentence carries information; the only mild inefficiency is that 'No account, no API key' and 'Failed calls not charged' are compact fragments rather than prose, which is fine for agent consumption.

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, three-optional-parameter read tool with no output schema, the description supplies everything an agent needs to decide and call: what data comes back, where it comes from, what it costs, how to pay, and the endpoint. Return-value structure would be nice but is the only minor 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 description coverage is 100%, so sort, limit and min_tvl_usd are already documented in the schema. The description adds nothing about their semantics (e.g. sort direction, whether min_tvl filters pools or protocol total) and instead spends its words on pricing and output fields.

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 resource ('live DeFi yields for stake.link-liquid'), enumerates the returned fields (APY, TVL, 7d APY change) and the data source (DefiLlama). The protocol name embedded in the tool differentiates it from the many sibling buy_yields_protocol_* / buy_yields_chain_* tools, though it never explicitly frames itself against them.

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: an agent can infer 'use this when you need yields for stake.link-liquid'. There is no explicit when-to-use or when-not-to-use statement, and no routing to chain-level or token-level yield siblings for broader queries.

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