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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely new behavior: the result is bounded to 25 newest payments, includes counterparties, and unranked ids return not-found because an agent with no payment history has no record. That error semantics is valuable context beyond the annotations.

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 tightly packed sentences with the payload contents front-loaded and the failure condition second. No filler, though the phrasing ('sell or show') is slightly ornate for the information conveyed.

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 carries the return-value burden and does so reasonably: rank, evidence, bindings, and 25 newest payments with counterparties. The only gap is a named alternative for retrieving a paid/fuller statement, which would round out the routing picture.

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% and the single 'id' parameter is documented as accepting token id, slug, or wallet address. The description adds nothing about the id beyond the schema, so the baseline of 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?

The description names a specific resource (one ranked agent's record) and enumerates its contents: rank with evidence, bindings, and the 25 newest payments with counterparties. It is clearly not a generic lookup, but it never names a sibling (e.g., agent_statement) to distinguish itself, leaving the boundary to inference.

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?

Usage is implied by the word 'free' and by the unranked-id error clause, suggesting a cheaper alternative exists for ranked agents, but no tool is named and no explicit when-to-use guidance is given. The agent must infer the routing itself.

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