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

Goes far beyond the annotations: describes archive-state limits, eth_getProof head-block window, flashblocks pending behavior, reth versions, history depth, refused method families, eth_getLogs pagination, and the zero-refund cut-off behavior on payment exhaustion. No contradiction with the 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?

Every sentence carries operational information and the core purpose is front-loaded, but the text is a dense wall of semicolon-separated details. It is appropriately sized for a complex RPC tool, though short bullet sections would improve scannability.

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?

Covers chain differences, method allow/refuse lists, payment mechanics, limits, pagination, and alternative endpoints, and delegates the exhaustive method list to /llms.txt. Combined with the input schema and annotations, an agent has enough context to call the tool correctly.

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?

Though schema coverage is 100%, the description adds crucial meaning: chain selects the node, params must be the exact JSON-RPC params array, and line is the optional payment credential. The concrete example ties chain, method, and params together clearly.

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?

States a specific verb and resource: it forwards JSON-RPC calls to Ethereum and Base archive nodes. It also distinguishes itself from siblings by naming sample_rpc for free availability checks and POST /rpc/{chain} for high-volume use.

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?

Explicitly tells the agent when to prefer alternatives: sample_rpc for checking node availability, POST /rpc/{chain} for volume, and warns that a call is cut when the balance empties. It also points to /llms.txt for the full per-chain method list, leaving no ambiguity about scope.

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