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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses the fallback behavior (caller APY omitted -> TVL-weighted blended rate of railed pools) and the valid APY range, but says nothing about the return type, rounding, or error conditions for invalid inputs.

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?

A single dense sentence with the purpose front-loaded and zero filler. It is packed but every clause (rate basis, APY bound) earns its place.

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 two-parameter computation tool with full schema coverage, the definition is nearly complete. The only gap is that no output schema exists and the description does not state what the return value looks like (presumably a dollar amount), though this is a small omission for an arithmetic tool.

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 both parameters are fully documented in the schema, including the APY bounds and the omitted-parameter fallback. The description largely restates that same information, adding no syntax or semantic detail beyond the schema.

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 verb ('computes') and resource ('the lump-sum capital whose yield alone covers a recurring monthly bill forever'), plus the rate basis used. An agent can immediately distinguish this calculation tool from the sibling lookup tools (find_pools, get_pool, get_pool_score).

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 through the computation's nature; there is no explicit when-to-use, when-not-to-use, or alternative named. Since no sibling performs a comparable calculation, the omission is minor, but no routing guidance is given.

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