Builder Journey

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

Beyond the annotations (which already declare read-only/idempotent/non-destructive), the description discloses the Pro-tier requirement, the fixed minFills=3 qualifying threshold, the per-wallet-then-aggregate computation, and the truncation bias that pushes day counts low, pointing to dataNotes. That is meaningful behavioral context the annotations cannot carry.

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?

It is front-loaded with the core purpose and every clause carries metric, caveat, or routing information, which is defensible given the absence of an output schema. It is still a dense run-on that could be broken into scannable sentences.

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 output schema, the description responsibly enumerates the returned fields and their semantics (e.g., concentration=1 means evenly spread, 0 when median is 0), defines the cohort universe and window, and flags the bias, leaving no material gap for correct 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?

Schema coverage is 100%, so the schema already documents both the builder pattern and useToonFormat, giving a baseline of 3. The description only restates that a 0x-hex builder address is taken and adds no format or value guidance beyond the schema; its claim of 'no other parameters' is also slightly loose given useToonFormat exists.

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 names the exact population, metrics, and computations (avgRevenueUsd, medianRevenueUsd, concentration, daysToPeak/Half/ThreeQuarters, peakDayDistribution) for a specific resource — a builder's acquisition cohort. It explicitly distinguishes itself from the sibling builder_lifecycle by scoping to the trailing-year cohort.

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 supplies an explicit trigger question ('how fast and how unevenly does builder X monetize a new user?') and a 'NOT ... builder_lifecycle covers' exclusion, so the agent knows both when to use it and which sibling to pick instead. It also states the Pro-tier prerequisite.

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