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

Annotations only mark it as read-only, idempotent, and non-destructive. The description adds rich behavioral context: READ-ONLY, no order placement or fund movement, auth requirements (X-Api-Key or x402 payment), cost per call, rate limit, and clarification that billing is not a side effect. It also notes the possibility of forwarding raw signed txs, which is a subtle exception to read-only behavior. This goes well beyond 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?

The description is well-structured with labeled sections (Purpose, Behavior, Auth, Cost, Rate, Returns, Guidelines, Tags), but it contains an obvious redundancy: the opening sentence 'Multi-endpoint Solana RPC proxy with automatic failover (Alchemy, public, Ankr) for any JSON-RPC method. Reliable Solana access.' is repeated verbatim in the Purpose section. This wastes tokens and slightly hampers conciseness.

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 all necessary aspects for a generic RPC proxy: purpose, behavior, auth, cost, rate limit, return type, and usage guidelines. It also includes a safety note about raw signed transactions. Given that an output schema exists, it doesn't need to detail return structures. The description stands alone as a complete guide for selection and 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?

The schema already has 100% parameter descriptions, so the baseline is 3. The description enhances param understanding by explaining that method is any JSON-RPC method, that params is the RPC parameter array, and by linking __x_payment to the x402 payment proof mechanism for retrying after HTTP 402. This adds useful context beyond the schema's minimal 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 it is a 'Multi-endpoint Solana RPC proxy with automatic failover (Alchemy, public, Ankr) for any JSON-RPC method.' This specific verb+resource+scope distinguishes it from sibling tools like cc.coinglass_data or cc.hyperliquid_data, which focus on specific data endpoints rather than a generic RPC proxy.

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 provides usage context: 'Forward JSON-RPC only. Prefer eth_call / read methods. Sending raw signed txs is possible if you pass them — that is your responsibility.' It also details auth, cost, and rate limits that guide when to use the tool. However, it does not explicitly mention alternatives or when NOT to use this tool, so it falls short of a 5.

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