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

Annotations already cover readOnly/idempotent/non-destructive, so the description's added value is the ordering guarantee (newest first) and the pagination model (cursor), both of which the agent needs to page correctly. It does not say how pagination terminates or whether meta.next_cursor is absent on the last page, which keeps it from a 5.

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?

A single dense sentence with the core identity front-loaded and the qualifying details (contents, ordering, pagination) packed into the tail. No filler and nothing repeated from the schema.

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 zero-required-parameter read tool with rich annotations and no output schema, the description covers what the entries are, their fields, ordering and pagination — enough to call it correctly. The one real gap is the ambiguous `status` filter, which neither the schema nor the description resolves.

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 limit and cursor are already fully documented and the description only echoes the paginated-with-cursor idea. Notably it says nothing about the `status` filter, and the schema's own wording ('Filter by ledger entry type') is odd against a parameter named status, so the description could have disambiguated but does not.

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 the resource precisely (ledger of the balance) and enumerates its contents — credits and debits from payments, payouts, fees and conversions — with amount, direction and time. That enumeration implicitly separates it from the single-resource siblings (list_payments, list_payouts), but no sibling is named explicitly, so it falls short of a 5.

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 only implied by content: it is the place to look for a historical, chronological record of balance movements. There is no statement contrasting it with get_balances (current balances) or with the per-resource list tools, so an agent must infer which one it wants.

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