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

Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint=false), so the description isn't burdened with that. It usefully adds ordering semantics ("newest first") and discloses the shape of each returned item (direction, counterparty, counterparty metadata), which is real value beyond structured fields; it stops short of describing truncation or pagination when limit is exceeded.

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 resource and ordering front-loaded, followed by the optional filter and its rationale. No filler and nothing repeated from the schema or annotations.

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 read-only listing tool with 100% schema coverage and no output schema, the description compensates by describing what each returned transfer contains. Nothing an agent needs to invoke it correctly 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 the baseline is 3. The description earns above baseline by framing what counterparty_category actually answers for the caller, adding intent-level meaning beyond the schema's "Only transfers whose counterparty is of this type." Other params (since/until/limit) are left entirely to the schema.

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 resource and operation: a wallet's recent transfers, newest first, with per-transfer direction and counterparty. It distinguishes itself from tracing/screening siblings implicitly (transfer listing with counterparty enrichment) but never names an alternative, so the differentiation is inferential.

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?

Gives one concrete usage case for the optional filter ("did this wallet deposit to a casino"), which implies the general when-to-use. However, it offers no exclusions and no routing against siblings like list_counterparties or trace_funds, so an agent must infer which tool to pick.

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