VeChain MCP Server

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

With no annotations, the description carries full burden but only states the basic action. It doesn't disclose critical behavioral traits like required permissions (e.g., token owner), whether this is a blockchain transaction (implying gas fees and confirmation time), irreversible nature, or rate limits. 'Approve' suggests a write operation, but details are missing.

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?

Single sentence, front-loaded with the core action, zero waste. Every word earns its place by clarifying the tool's purpose and parameter context efficiently.

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 complexity (blockchain token approval with 3 parameters), no annotations, no output schema, and low schema coverage, the description is incomplete. It lacks details on behavioral aspects (e.g., transaction lifecycle, errors), return values, or usage context, making it inadequate for safe agent invocation.

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%, so the description must compensate. It adds meaning by specifying 'amount' is in base units (e.g., wei, not decimals) and that 'tokenAddress' and 'spender' relate to ERC20 tokens, but doesn't explain parameter formats (e.g., hex addresses) or constraints beyond what the schema's patterns imply. Baseline 3 as it partially compensates for low coverage.

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 ('Approve') and resource ('an amount of an ERC20 token'), specifying it's for a spender. It distinguishes from siblings like 'revoke_token_approval_evm' (revoke vs approve) and 'get_token_allowance_evm' (get vs approve), but doesn't explicitly differentiate from 'send_token' (which transfers tokens rather than approves spending).

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 'revoke_token_approval_evm' or 'send_token', nor prerequisites such as token ownership or network conditions. The description implies usage for token approval but lacks explicit context or exclusions.

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