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

With no annotations provided, the description carries the disclosure burden. It adds useful behavioral context by stating 'No oracle key' and 'Paid $0.01 USDC Base x402,' covering auth and cost. It does not explicitly state that the tool is read-only, but 'gas oracle' strongly implies a non-mutating lookup.

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?

Every clause earns its place: what the tool is, what it returns, when to use it, auth requirements, and cost. The core purpose is front-loaded, and the entire description is compact with 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?

For a zero-parameter oracle with no output schema and no annotations, the description provides the essential return values, usage timing, auth requirement, and payment cost. An agent has enough information to decide whether to call this tool and what to expect from it.

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 no parameters and the schema coverage is 100%, so there are no parameter semantics to explain. The description still adds value by enumerating the data points returned, helping an agent interpret results without an output schema.

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 identifies the tool as a Base network EIP-1559 gas oracle and specifies its outputs: base fee, priority tips, and 21k transfer cost. This makes it immediately distinct from sibling tools base_ens and base_price, which cover ENS and pricing rather than gas.

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 explicitly instructs when to use the tool: 'Use before signing a tx.' This gives clear actionable context. It does not mention alternatives or exclusions, but the instruction is specific enough for an agent to decide when this tool applies.

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