builder_stats

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

Without annotations, the description carries the full transparency burden. It discloses the cost ($0.25 USDC per call), which is a key behavioral trait, and lists what data is returned (acceptance rates, block counts, health status). It does not mention data freshness or rate limits, but the cost and content disclosure is solid.

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 three concise sentences, each earning its place: the first states the core purpose and builders, the second details the metrics, and the third notes the cost. It is front-loaded and free of fluff.

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 no-parameter, no-output-schema tool, the description is complete. It tells the agent exactly what data will be returned and informs about the required payment. No additional context is needed for selection or invocation.

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 has zero parameters, so the schema is empty. According to the rubric, 0 params earns a baseline of 4. The description adds meaningful context about the output without needing to describe parameters.

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 specifies the exact resource (builder statistics) and action (returns), names the specific Ethereum block builders (Flashbots, Titan, Beaver, BuilderNet, and Quasar), and lists the metrics (acceptance rates, block counts, health status). This clearly distinguishes it from sibling tools like liquidation_watchlist or agent_intelligence.

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 description implies that the tool should be used when builder statistics are needed, but it does not provide explicit when-to-use guidance or mention alternatives. Since the purpose is narrow and distinct from siblings, the usage context is somewhat acknowledged but not formally stated.

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