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

With no annotations, the description carries the full burden, and it does disclose two real behavioral facts: the data source (Alchemy) and the paid cost model ($0.004 USDC on Base per call), which is genuinely useful for cost-aware agents. However, it says nothing about freshness, caching, failure modes, or what the response contains.

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?

Two short sentences with zero padding, and the core purpose (gas fees for a chain) is front-loaded ahead of the source and payment metadata. Every clause earns its place.

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 simple, single-parameter read tool with no output schema or annotations, the description covers purpose, data provenance, and cost. The only real gap is the shape of the returned fee data (units, fields), which an agent must guess.

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 already lists the valid values (ethereum, base, arbitrum, polygon, optimism) plus a default, so the schema does the heavy lifting. The description adds no format or semantic detail beyond it, warranting the baseline 3.

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: retrieves 'current base fee + priority fee (gas prices) for a chain.' The gas-price resource is distinct from the price-oriented siblings (cortex_prices, cortex_token_price, cortex_aggregate_prices), so an agent can separate it by topic, though the description never names an alternative explicitly.

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 phrase 'for a chain' implies the usage context, and the gas-fee subject matter is inherently self-routing, but there is no explicit when-to-use, when-not-to-use, or named alternative among the 17 siblings. Usage 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.