MCP Etherscan 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 of behavioral disclosure. It states what the tool does but lacks details on traits like error handling (e.g., for non-ENS addresses), performance (e.g., response time), or side effects (e.g., network calls). This leaves gaps for an agent to understand operational behavior beyond the basic function.

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, clear sentence that front-loads the core purpose without unnecessary words. It efficiently communicates the tool's function, earning its place with zero waste, making it highly concise and well-structured for quick understanding.

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 low complexity (1 parameter, no output schema, no annotations), the description is minimally complete. It covers the basic purpose but lacks context on usage, behavior, or output details. Without annotations or output schema, more guidance would be helpful, but it meets the minimum viable threshold for such a simple tool.

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 has 100% description coverage, with the 'address' parameter well-documented in format and pattern. The description adds no additional parameter semantics beyond implying the address is used to fetch the ENS name. 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 with a specific verb ('Get') and resource ('ENS name'), and identifies the target ('Ethereum address'). It distinguishes from siblings like 'check-balance' or 'get-transactions' by focusing on ENS name resolution. However, it doesn't explicitly differentiate from potential similar tools not present in the sibling list, keeping it at 4 rather than 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. It doesn't mention prerequisites (e.g., needing an address), exclusions (e.g., invalid addresses), or comparisons to siblings like 'get-contract-abi' for different data types. Usage is implied from the purpose but not explicitly stated, resulting in minimal guidance.

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