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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful non-schema context: the exact cost (0.0060 USDC per call) and the fact that payment is always taken ('premium: always paid'). It stops short of describing freshness, caching, or failure behavior, so a 4 rather than 5.

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?

Front-loaded with the bundle contents, then the routing guidance, then pricing; each sentence earns its place. Slightly dense with parenthetical enumerations, but no filler.

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?

With no input parameters, no output schema, and annotations carrying the read-only/open-world profile, the description supplies everything needed to call it correctly: what it returns, when to choose it, and its cost. Nothing material is missing.

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 there is nothing for the description to clarify; the baseline for a parameterless tool is 4. The description correctly consumes the call with no argument guidance needed.

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 resource (a bundled Base market snapshot of gas and WETH/USDC DEX pricing), enumerating the exact components returned (base fee, priority-fee percentiles, congestion, spot price, gross spread) and the venues queried. It is clearly distinguishable from the individual gas-optimizer and dex-arbitrage siblings it aggregates.

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 states when to use it (want both gas and DEX pricing in a single cheaper call), when not to (do not also call gas-optimizer or dex-arbitrage), and the alternative condition (prefer individual tools if you need only one). This is a complete routing instruction.

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