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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly states that data refreshes every 3 hours, includes its source and observation date, and explicitly warns that it is not real-time, preventing a common misunderstanding based on the tool name 'live_data'.

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 front-loaded with the core value proposition, followed by a precise list of supported data categories and a critical caveat. Every sentence earns its place, and there is no redundant or filler language.

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-parameter tool with no output schema, the description is largely self-sufficient: it names the assets, refresh interval, source/observation-date metadata, and the non-real-time caveat. It does not specify output format or units, but that is not required for correct invocation.

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 and the schema has 100% coverage, so the description does not need to explain parameter semantics. The listing of supported asset categories and symbols adds useful context beyond the empty 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 clearly identifies the tool as a provider of latest reference values across a specific set of crypto, FX, and macro assets. It is unambiguous about the resource, though it lacks an explicit verb and does not differentiate itself from sibling tools by name.

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 refresh cadence and the explicit 'NOT real-time ticks' statement imply when the tool should be used and when it should not, but no alternative tools or explicit selection criteria are mentioned. Usage guidance is present only implicitly.

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