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

Annotations already declare read-only, open-world, idempotent, and non-destructive behavior. The description adds valuable context beyond these: the tool is free, capped per hour, requires no wallet, defaults to base and eth_blockNumber, and explains the semantic limitation that a matching result proves data authenticity but not operator identity. This is substantial behavioral disclosure.

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 compact yet information-dense. It front-loads the core purpose, then provides usage constraints, an explicit alternative, and a working example. Every sentence contributes either to understanding, safe invocation, or correct tool selection, with no wasted words.

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 purpose, safety profile, defaults, limits, alternative routing, and interpretation caveats. Given the rich input schema and output schema, nothing essential is missing for an agent to invoke this tool correctly and understand what the result means.

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 already documents all three parameters including defaults and allowed values. The description reinforces this by stating chain defaults to base and method to eth_blockNumber, and gives a concrete example, but it doesn't add meaning beyond what the schema already provides.

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 states a specific purpose: verifying that a node is real by sending a read-only sample call that can be compared against other sources. It clearly distinguishes itself from call_rpc, and the verb 'checks' plus the resource 'the node' make the action concrete and unambiguous.

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 gives explicit guidance on when to use this tool: for free, capped, read-only sample checks. It also states the exact condition to use the alternative instead — 'For any other method, or with no cap, call_rpc.' This leaves no ambiguity about tool selection.

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