Crypto Price MCP

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

The description adds key behavior beyond the readOnly annotation: the coin parameter is a CoinGecko slug with automatic mapping for common tickers, vs_currency defaults to usd and accepts fiat, and the output is informational only. It also states the return fields, providing useful context not available in annotations.

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 front-loaded with purpose and usage, but it repeats the return fields ('Current price, market cap, and 24h change' and 'Returns price, market cap, and 24h % change'), which is redundant. Otherwise, it is structured and not overly verbose.

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?

The description covers purpose, usage, both parameters, return data, data source, and a disclaimer. With an output schema present and annotations providing read-only safety, the description is complete for an agent to select and invoke the tool correctly. No major gaps.

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?

Schema coverage is 0%, so the description fully explains both parameters. It clarifies that 'coin' is a lowercase slug, lists common tickers that are auto-mapped, and warns that anything else must be the exact slug. It also explains 'vs_currency' default and supported fiat currencies, compensating well for missing schema descriptions.

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 current price, market cap, and 24h change for a cryptocurrency from CoinGecko, and provides explicit example questions like 'price of bitcoin'. Even though it lacks an explicit verb, it is unambiguous and specific, and the examples strengthen purpose clarity.

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?

It explicitly says 'Use for ... style questions', giving clear when-to-use context. It does not specify when not to use or alternatives, but there are no sibling tools, so no exclusions are needed. This is clear contextual guidance.

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