EVM MCP Server

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

With no annotations, the description carries full burden but provides minimal behavioral information. It states the action but doesn't disclose critical traits: that this is a write operation requiring private key, that it will incur gas fees, that it's irreversible once confirmed, or what the return value contains. The schema's security note about private key handling is helpful but not in the description itself.

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?

Extremely concise single sentence with zero wasted words. The description is front-loaded with the core action and gets straight to the point without unnecessary elaboration.

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 write operation with 5 parameters, no annotations, and no output schema, the description is incomplete. It doesn't explain what happens after invocation (transaction hash returned? wait for confirmation?), doesn't mention gas estimation needs, and provides no context about blockchain transaction characteristics. The schema covers parameters well, but the description lacks crucial behavioral context.

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 100%, so the schema fully documents all 5 parameters. The description adds no additional parameter information beyond what's already in the schema descriptions. Baseline 3 is appropriate when schema does all the parameter documentation work.

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 ('transfer') and resource ('ERC20 tokens'), specifying the destination ('to an address'). It distinguishes from siblings like transfer_eth (native currency) and transfer_erc1155 (different token standard), but doesn't explicitly differentiate from transfer_erc20 which appears to be a duplicate tool.

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?

No guidance on when to use this tool versus alternatives like transfer_eth or transfer_erc1155. The description doesn't mention prerequisites (e.g., needing token approval via approve_token_spending) or context for selecting this over similar tools.

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