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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true, idempotentHint=false), so the bar is lower. The description adds genuinely non-structural behavior: a per-call USDC charge via x402 or prepaid credits, plus free-trial eligibility, which an agent needs before invoking. It does not contradict any annotation.

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?

Two dense sentences with the purpose front-loaded and pricing last, in the right order for an agent. The long comma-list of return fields is slightly heavy but every element is informative.

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 a 3-param schema at full coverage and an output schema present, the description need not explain return values, yet it usefully summarizes them for tool selection. It also discloses cost and trial status, which is all an agent needs to call it correctly; only alternative-tool routing is absent.

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 'protocol', 'days', and 'limit' are fully documented in the schema. The description mentions vesting cliffs, emission changes, and % of supply but does not clarify the parameters themselves, so the baseline 3 applies.

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?

States a specific verb and resource ('upcoming token unlocks for a project') and enumerates the returned fields: dates, amounts, % of supply, USD value, recipients, sell pressure, and 30/90-day totals. This clearly distinguishes it from sibling token-* tools like token-holders or token-whales without needing to name them.

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 never says when to reach for this tool versus alternatives such as token-holders or token-report, nor does it state preconditions beyond the price. The only usage-adjacent content is billing ('$0.005 per call', 'free trial'), which is not selection guidance.

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