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 does this well by stating the data is real-time, the service is free with no signup, and requests are rate-limited to 5 per minute. It does not detail error behavior or response format, but for a simple no-parameter tool this is solid coverage.

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 a single concise sentence that front-loads the core purpose and then adds two high-value usage constraints. Every clause earns its place with no redundancy or filler.

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 minimal complexity—no parameters, no output schema, and no annotations—the description is largely complete. It covers what data is returned, the real-time nature, access requirements, and rate limits. It could mention output format or rate-limit failure behavior, but these are not critical for basic 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 input schema has zero parameters, so the baseline is 4. The description adds no parameter details, but none are needed since the tool takes no inputs and the schema coverage is effectively complete.

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 resource as real-time BTC/ETH/SOL prices, which distinguishes it from sibling tools focused on analysis, quotes, or research reports. It lacks an explicit verb like 'retrieves' or 'returns,' but the tool name and phrasing make the purpose 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 this tool—when real-time prices for BTC, ETH, or SOL are needed—and provides useful context like free access and rate limits. However, it does not explicitly state when to prefer this over sibling tools like get_market_quote or get_market_analysis.

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