Etherscan MCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool retrieves token holders but doesn't describe what 'holders' entails (e.g., addresses with balances, excluding zero balances), how data is returned (e.g., list format, pagination), or any limitations (e.g., rate limits, large datasets). For a read operation with no annotation coverage, this is a significant gap in transparency.

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, efficient sentence: 'Get the token holders for a given token address'. It is front-loaded with the core action and resource, with zero wasted words. Every part of the sentence earns its place by directly conveying the tool's purpose without redundancy or fluff.

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 (fetching token holders) and the absence of annotations and output schema, the description is minimally complete. It states what the tool does but lacks details on behavior, return values, or usage context. While it covers the basic purpose, it doesn't fully address the gaps left by missing structured data, making it adequate but with clear room for improvement.

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 schema description coverage is 100%, with both parameters ('chain_id' and 'token_address') documented in the schema. The description adds no additional meaning beyond implying the token address is used to fetch holders, which is already clear from the schema. Since the schema does the heavy lifting, the baseline score of 3 is appropriate, as the description doesn't compensate but doesn't detract either.

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 the token holders for a given token address'. It specifies the verb ('Get') and resource ('token holders'), and distinguishes it from siblings like 'get_token_holders_count' (which counts holders) and 'get_token_balance' (which checks individual balances). However, it doesn't explicitly differentiate from all siblings, such as 'get_total_supply', which might involve similar token data.

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. It doesn't mention when to choose this over 'get_token_holders_count' for counting holders or 'get_token_balance' for checking specific balances, nor does it specify prerequisites like needing a valid token address. This lack of context leaves the agent to infer usage from tool names alone.

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