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

With no annotations, the description carries the full behavioral burden. It discloses rich output details (current/next base fee, priority tiers, cost per action in ETH and USD), the data source for tiers ('last 20 blocks'), and the access cost ('$0.002 USDC via x402'). It does not explicitly state read-only safety or rate limits, though these are strongly implied by 'Input: none' and the estimation nature.

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 front-loaded with the usage condition, then input, output, and a concrete example. Every sentence adds necessary information; the output list is dense but justified because no output schema is provided.

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?

Given the absence of an output schema and annotations, the description fully explains return values, input expectations, data freshness, and pricing. An agent has everything needed to call and interpret the 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 the baseline is 4. The description confirms 'Input: none', which is sufficient given the empty input 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 states a specific verb and resource: 'price or time a Base transaction', and then enumerates the exact output fields (base fee, priority tiers, cost per action). It is clearly distinct from all sibling tools, none of which perform gas/fee estimation.

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 gives an explicit usage condition: 'Use when an agent must price or time a Base transaction.' No alternatives are needed because no sibling tool covers this purpose, but the description lacks explicit when-not guidance (e.g., for non-Base chains).

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