REI Crypto MCP Server

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

No annotations are provided, so the description carries the full burden. It mentions the action ('Get') but doesn't disclose behavioral traits like whether this is a read-only operation, potential rate limits, authentication needs, error handling, or what the output looks like. For a tool with no annotation coverage, this is a significant gap.

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 appropriately sized and front-loaded, with the core purpose stated first followed by parameter details. It avoids unnecessary fluff, though the inclusion of 'GET /coins/prices/first/{coins}' (which appears to be an API endpoint) adds minor redundancy.

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 moderate complexity (one parameter, no annotations, but with an output schema), the description is minimally adequate. It covers the purpose and parameter format but lacks behavioral context. The presence of an output schema means return values are documented elsewhere, so the description doesn't need to explain them.

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 description coverage is 0%, but the description compensates by explaining the 'coins' parameter: 'comma-separated tokens in format {chain}:{address}'. This adds crucial semantic context beyond the schema's basic type information. With only one parameter, this is sufficient for a high score.

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's purpose: 'Get earliest timestamp price record for coins.' It specifies the verb ('Get'), resource ('price record'), and scope ('earliest timestamp'). However, it doesn't explicitly differentiate from sibling tools like 'get_current_prices' or 'get_historical_prices', which would require a 5.

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 provides no guidance on when to use this tool versus alternatives. With many sibling tools related to prices (e.g., 'get_current_prices', 'get_historical_prices'), there's no mention of when this specific 'first price record' tool is appropriate or what distinguishes it from other price-related tools.

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