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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds valuable operational context beyond annotations: the data source ('mainnet RPC: recent performance samples, epoch info, prioritization fees'), pricing ('free'), and error behavior ('returns isError with a message for invalid input or an upstream failure (not charged)').

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 dense but front-loaded with the returned metrics, followed by source, usage guidance, pricing, and errors. The external URL parenthetical is slightly heavy, but every paragraph carries actionable information.

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?

An output schema exists, so return-value documentation is not required in the description. The description still clearly enumerates the metric coverage, data source, pricing, and error behavior, making it complete for a read-only, zero-parameter network-status tool.

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 tool takes zero parameters, so parameter semantics are not applicable. Per the baseline for 0-parameter tools, this is a 4.

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 uses a specific resource and metric set: 'Solana right now: TPS (total and non-vote), slot and block height, epoch progress and ETA, priority-fee percentiles, cluster version.' It explicitly distinguishes Solana fee/TPS usage from EVM and BTC fee tools by naming gas_now as the alternative.

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?

It provides an explicit when-to-use section: 'For Solana fees/TPS; for EVM and BTC fee costs use gas_now.' This directly routes the agent between this tool and a relevant alternative.

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