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

Annotations already declare readOnlyHint and openWorldHint. The description adds important behavioral details: 'Returns success status and raw return data for each call' and explains the effect of allowFailure. No contradiction with annotations.

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?

Three concise sentences, each adding value: purpose, return format, and a usage tip. No 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?

The description covers the operation, return format, and failure handling, which is sufficient for a read-only multicall tool. It doesn't mention decoding raw data, but sibling decode tools cover that. Overall quite complete.

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 coverage is 100%, so baseline is 3. The description enriches understanding by explaining the purpose of allowFailure and the return format, going beyond the schema's simple parameter descriptions.

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 function: 'Batch multiple read-only contract calls into a single RPC round trip via Multicall3 on Mezo'. It specifies the network, the contract, and the action, making it distinct from sibling tools like eth_multicall or mezo_testnet_multicall.

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 implies usage when batching multiple read-only calls is needed, and provides a specific tip about allowFailure, but it does not explicitly compare this tool to alternatives or state when not to use it. It lacks explicit 'when to use vs. other tools' guidance.

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