navi_crypto_prices

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

With no annotations provided, the description carries the burden of behavioral disclosure. It states the data source (CoinGecko), output structure (price, change, market cap), and importantly discloses the per-call cost and settlement mechanism (x402, USDC on Base). This is valuable beyond the schema. It does not mention rate limits or error behavior, but the disclosed traits are significant.

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 two sentences plus a short parenthetical. It leads with the core purpose, then adds data source and return fields, and ends with pricing. Every sentence provides distinct value 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?

For a simple list tool with one optional parameter and no output schema, the description covers the essential information: what it returns, data source, and cost. It lacks details like coin ID format limitations or failure handling, but the description is sufficient for an agent to invoke it correctly in most use cases.

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 already provides 100% coverage for the single 'coins' parameter, describing comma-separated coin IDs with an example. The description adds no new parameter semantics beyond confirming the coin names, so the baseline score of 3 is appropriate.

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 returns real-time cryptocurrency prices for major coins, and specifies the exact output fields (price, 24h change, market cap). It differentiates from siblings like navi_crypto_indicator by focusing on price quotes rather than technical indicators or health checks.

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 gives context that this provides current prices from CoinGecko and notes the paid nature with cost and settlement details. It implies use when needing real-time USD price data, but does not explicitly exclude alternatives or provide when-not-to-use guidance. Clear enough for most scenarios.

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