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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the bar is lower, yet the description still adds substantial behavioral context beyond them: a heuristic-confidence caveat, the exact output shape, and full invocation economics (x402 pricing on Base, prepaid x-credit-token header for unlimited calls, 1 free call/day, no API key). This is exactly the extra information an agent needs before paying for a call.

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 core purpose and interpretation rules are front-loaded in a dense, well-organized first paragraph, and the required parameter is called out explicitly. The trailing pricing/legal sentences are longer than ideal but earn their place by telling the agent about cost and auth before invocation.

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 an output schema exists, return values need little elaboration, and the description still summarizes them ('first holders and a verdict'). With annotations covering safety, the description fills the remaining gaps an agent needs: heuristic limitations, payment/auth mode, and the sibling relationship. Nothing material is missing.

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%, so both parameters are already documented in the schema, including the default for 'first'. The description repeats 'first= (default 40)' and 'Required input: address' without adding format, range, or trade-off guidance (e.g., what a larger window costs or reveals). Baseline 3 is appropriate when the schema carries the load.

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 concrete operation ('reads a token's EARLIEST transfers') and the exact question it answers ('Were the first buyers a coordinated bundle, or organic?'), plus the output ('the first holders and a verdict'). It also positions itself against a named sibling ('pairs with b20-launch-radar'), so the agent can distinguish it without opening the schema.

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 clear usage context: this is the 'launch-quality read' complementing b20-launch-radar, and it explicitly frames itself as 'a heuristic, not proof'. It also explains how to interpret each outcome (single-block cluster = sniped, few holders = concentration risk, spread = organic). It stops short of stating when NOT to use it or naming an alternative for related questions (e.g., rug_score or token_risk), so it is not a full 5.

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