add_supported_cryptocurrency

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

The description adds context beyond the minimal idempotentHint annotation by identifying the resource as the 'supported manual-crypto list' and the input as a CoinGecko URL. However, it does not disclose what happens on duplicate submission or invalid URLs, so behavioral transparency is moderate.

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 consists of two sentences, is front-loaded with the primary action, and contains no unnecessary details. Every word contributes to understanding the tool's purpose and usage.

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 single-parameter mutation with no output schema, the description sufficiently explains the operation and its use condition. It does not describe the response or error behavior, but the overall context is adequate for a tool of this simplicity.

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 provides a complete description of the coingecko_url parameter, including the URL format and an example, so the tool description adds no extra semantic value beyond repeating that it is a CoinGecko URL. Since schema coverage is 100%, 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 action ('Add a new cryptocurrency to the supported manual-crypto list') and the method ('by submitting its CoinGecko coin-page URL'). It also distinguishes the tool from the sibling get_supported_cryptocurrencies by specifying when it is needed.

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 explicitly provides a usage condition: 'Only needed when get_supported_cryptocurrencies does not already list the symbol you want to track.' This names the alternative tool and gives clear guidance on when to use this one.

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