list_currencies

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

Beyond the read-only annotation, the description discloses that the data is cached (reference data) and that the complete list is returned in one response (no pagination). This gives the agent a clear expectation of the tool's behavior and performance characteristics.

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 concise yet information-dense, covering all essential aspects in a single sentence. It is well-structured, starting with the action, then the content, purpose, and behavioral notes, with no wasted words.

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?

Given the tool's simplicity (no parameters, no output schema), the description is fully complete. It explains what the data contains, its intended use, and its delivery characteristics, leaving no ambiguity for the agent.

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 no parameters, and the description correctly does not attempt to describe any. Since there are zero parameters, the baseline of 4 is appropriate; the description adds no parameter-related confusion.

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 states the tool lists Capsule's currency dictionary, specifying the exact fields (ISO 4217 code, symbol, name) and row count (80). It also explains its purpose as providing valid codes for the opportunity's `value.currency` field, which is unambiguous.

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 description implies when to use it: whenever valid currency codes are needed for `value.currency`. It also mentions that it is cached reference data, suggesting it can be called infrequently. However, it does not explicitly state 'use this when...', so a small gap remains.

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