List currencies

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds useful context on the return content and explicitly notes no parameters are required to retrieve the full set, which helps the agent understand the call is a full-dump read.

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?

Markdown headings front-load the purpose well, but the content is repetitive: the opening paragraph, 'What You Get', and 'Quick Start' restate the same currency codes/names/country mapping three times. For a simple zero-input list tool this is oversized.

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 read-only reference-data endpoint with no output schema, the description adequately covers what is returned. The only gap is that it never hints at result size or pagination, which matters for an open-world 'return all' call.

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?

There is one parameter (timeout) with 100% schema description coverage, so the schema already does the work. The description's 'No parameters required' is accurate since timeout is optional infrastructure, but it adds no syntax or semantic 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 all available currencies'), and states the exact payload (codes, names, country mappings). It is clearly distinguishable from siblings like get_data_countries or get_data_cities that deal with other reference data.

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 'When to Use' section gives concrete contexts (dropdowns, price display, conversion, booking endpoints), which is more than implied usage. It stops short of naming alternatives or when-not-to-use conditions, so it is not a 5.

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