Get the $2DAI token price

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

The description adds key behavioral details beyond the readOnlyHint annotation: the quote is served from a cache, never triggers a live refresh, and staleness is included. It also notes the cost is zero. This provides a clear safety and reliability profile.

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 three concise sentences, front-loading the core purpose. Each sentence adds a distinct detail (scope, caching, cost), without redundancy.

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 parameterless read-only tool, the description fully covers the essential context: what it returns, how fresh it is, the access scope, and cost. No output schema is present, but the description compensates by explaining the staleness indicator.

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?

The tool has zero parameters, so schema coverage is total. The description doesn't need to explain parameters; it instead explains the output's nature. This meets the baseline for a parameterless tool.

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 clearly identifies the tool as returning the cached $2DAI/USD quote. It specifies the resource ($2DAI price) and the nature (cached quote), distinguishing it from other tools in the sibling list that handle accounts, creations, or wallet operations.

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?

It states the scope requirement ('ordinary read scope'), implies it's for indicative quotes due to cache, and clarifies that no finance scope is needed. However, it doesn't explicitly say when not to use it or name an alternative, but as the only price tool, the context is sufficient.

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