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

The description calls this 'Read-only cash-settlement summary' while annotations declare readOnlyHint=false, a direct conflict about the tool's safety profile. Beyond that, it adds nothing about sums being computed server-side or what the statement contains beyond the listed fields.

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 front-loaded sentence with the key claim first and the parenthetical field list kept tight. Slightly dense in the middle clause, but no filler.

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?

An output schema exists, so return values need not be explained, and both parameters are covered. However, the contradiction with the readOnly annotation leaves an agent uncertain whether calling this is a safe read, which is critical missing context for a no-annotation-compatible mutation flag.

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 0%, so the description must carry the load and largely does: it defines the scope of 'buyer' (whose retirements) and gives 'since' both its semantics (incremental window) and its format (ISO-8601), which the bare schema 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?

States a specific verb and resource — a read-only settlement summary of a buyer's retirements, with the exact sums included. It clearly separates this aggregate statement from per-record siblings like get_purchase or verify_retirement, though it never names an alternative.

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?

The phrase 'the statement a human settles in one transfer' implies the settlement reconciliation use case, and 'optionally since an ISO-8601 timestamp' implies incremental statements. There is no explicit when-not guidance and no sibling tool is named as an alternative.

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