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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds one genuinely behavioral detail beyond the schema: results are ordered newest first, plus that pagination is cursor-based. It says nothing about maximum page size, default limit, or how the next cursor is obtained from the response.

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 tight sentences: the first establishes what the records are and their ordering, the second covers filtering and pagination. Nothing is redundant and the most important identifying information is front-loaded.

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, fully described seven-parameter list tool with annotations covering safety, the description supplies the essentials (content, ordering, filter axes, pagination). The remaining gap is that with no output schema, it never indicates that the cursor for the next page comes from the previous response, so an agent must infer the loop.

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 every parameter is already documented and the baseline is 3. The description's only added meaning is that the free-text filter targets the 'reference' field (mapping to the opaque q parameter), which is a small but real clarification; date/kind/cursor semantics are merely restated.

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 entries) and enumerates exactly what appears in them (topups, call/AI debits, number rentals), which distinguishes it from the balance/spend siblings get_wallet_balance and get_ai_spend without naming them. It is a clear, specific list operation, though it never explicitly contrasts itself with those siblings.

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?

It tells the agent how to narrow results (kind, reference, date range) and how to page, which implies the use case of auditing transaction history. However, it gives no explicit when-to-use guidance, no statement that it is not for computing totals or building reports (a Pro/report-tool concern per the purpose param), and no named alternatives.

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