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

With no annotations, the description bears the full burden of behavioral disclosure. It adds useful context ('Data from 19K+ DeFi pools via DeFiLlama') but does not explicitly state that this is a read-only operation, how results are sorted, or potential caveats like pool risk or data freshness. This is adequate but not rich.

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?

The description is two concise sentences: the first states the primary purpose and scope, the second lists filter options and dataset provenance. No word is wasted, and the structure front-loads the most critical 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?

For a simple query tool with optional params and no output schema, the description covers purpose, scope, filters, and data source. It could explicitly mention sorting order or output format, but the task is straightforward enough that these omissions are minor.

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%: every parameter has a description, so the baseline is 3. The description merely restates the filter options (min TVL, chain, stablecoin-only) without adding deeper meaning or usage nuance beyond what the schema already provides.

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 opens with 'Get the highest APY yield pools across all chains and protocols,' which is a specific verb-resource pairing and explicitly differentiates from sibling tools like chain_yields by emphasizing global coverage and top APY ranking. It also clearly mentions the filtering dimensions, leaving no ambiguity about what the tool does.

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 provides explicit usage scenarios via 'Filter by min TVL, chain, stablecoin-only,' giving clear context for how to narrow results. However, it does not mention when to prefer this tool over specific siblings (e.g., stablecoin_yield or risk_adjusted) or any exclusions, so it stops short of a full 5.

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