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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, covering the safety profile. The description adds chain-type-dependent content behavior (EVM vs Solana fields), but with an output schema already present, most of the return-field detail is redundant. No auth or rate-limit context is provided, so a 3 is appropriate.

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 tightly packed sentences: purpose and outputs first, then the when-to-use, then alternatives. Front-loaded and no sentence is wasted.

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?

For a read-only, idempotent, single-parameter tool with a full output schema and complete annotation coverage, the description supplies everything an agent needs to select and invoke it correctly, including chain-family scoping and sibling routing.

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% and the single chain parameter is fully documented in the schema with enum values and a default. The description adds no chain-specific parameter syntax or constraints beyond what the schema already carries, so the baseline 3 holds.

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 (Get) and resource (current gas/fee data), then breaks down the exact outputs by chain family (EVM: base fee, priority fee, predictions; Solana: priority fees, TPS, congestion). It also names the three closely-related siblings it is not, so an agent can distinguish it without opening any schema.

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?

Explicit positive guidance ('Use for the current fee snapshot before submitting a transaction') plus explicit alternatives with their selection conditions: gas.history for past samples, gas.predict for a forecast, gas.optimize for timing advice. Nothing is left to inference.

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