Get Currencies

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds a genuine non-obvious trait: 'Results are cached,' which informs the agent that data may be stale or not freshly fetched. It does not mention cache duration, but for a simple no-param read tool this is sufficient.

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 short sentences, both informative: the first states the purpose, the second discloses caching behavior. There is no filler, repetition, or unnecessary detail.

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 read-only lookup with an output schema present, the description is complete. It states what the tool returns and the one relevant behavioral nuance (caching), and it does not need to explain return values because the output schema covers that.

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 the schema is vacuous and there is nothing to document. The description adds value by clarifying exactly what data is returned (currency codes and symbols), which is the relevant semantic content for this 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 names a specific verb ('Get'), a precise resource ('all supported currency codes and symbols'), and this clearly distinguishes it from the sibling tools, none of which overlap with a currency-list lookup. There is no ambiguity about what the tool returns.

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?

There is no explicit when-to-use guidance, exclusions, or named alternatives. However, the tool is a zero-parameter getter for a unique domain, so the intended use is reasonably implied. Still, the description leaves the agent to infer context rather than stating it.

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