get_rates

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is fully covered. The description adds only that data is real-time and aggregated across two protocols; freshness/caching behavior is left to the schema's refresh parameter rather than the description.

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 tight sentences, zero filler, with the resource, protocols, and chain front-loaded before the profitability note. Every clause carries 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?

An output schema exists, so return values need not be explained, and annotations cover safety; the description supplies protocol and chain scope plus the profitability signal. It could still note aggregation or update cadence, but nothing essential for correct invocation is missing.

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?

With a single parameter at 100% schema description coverage, the schema fully documents 'refresh' and its default. The description contributes only the generic notion of 'real-time' data, which loosely maps to the refresh semantics but adds no format or syntax 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?

The description names a specific verb and resource ('Get real-time supply APYs'), scopes it to concrete protocols and chain (Aave V3, Morpho, Base Mainnet), and is clearly distinct from the siblings get_quote and build_payment. An agent can identify the tool's domain without opening the schema.

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 most profitable protocol for capital recovery' suggests when the tool is useful, but there is no explicit when-to-use/when-not guidance and no routing against get_quote or build_payment, which an agent may need to disambiguate rate-checking from quoting.

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