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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. Beyond that, the description adds real value by disclosing the return shape (time, epoch, gas totals) and that transactions are rendered as one-line sentences, plus the default-to-newest behavior for "latest". It omits any indication of size/pagination for checkpoints with many transactions.

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?

Three short units — payload description, usage sentence, example call — with the return contents front-loaded and zero redundant wording. Nothing could be removed without losing information.

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 single optional-parameter tool with no output schema, the description carries the necessary burden by summarizing the returned fields and their formatting. The only gap is the absence of any note on response size or how many transactions a checkpoint may include.

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 defines seq, and the description's meaning-add is modest but real: it spells out the "latest" sentinel behavior and supplies a concrete invocation example ({ seq: "latest" }). That goes slightly beyond the schema's terse "Checkpoint sequence number, or latest."

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 (a checkpoint), the lookup key (sequence number or "latest"), and the payload returned (time, epoch, gas totals, transactions). It is clearly distinct from siblings like events, trace_funds, or explain_transaction, though it never explicitly contrasts itself with any of 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?

"Use it to see what is happening on chain right now" gives one concrete scenario, which is enough to imply a live-state read. However, it offers no when-not guidance and does not point to any alternative sibling (e.g., events or wallet_history) for historical or filtered views.

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