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

With no annotations, the description carries the full burden. It discloses that the tool enforces a finalized-only freshness contract, derives a cross_check_status, and wraps results in a proof envelope—valuable context beyond simply 'returns data.' It does not describe error conditions or access requirements, but these are less critical for a read-only query.

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 sentences, front-loaded with the core action, and no fluff. The second sentence adds meaning by explaining the freshness contract and proof envelope, making every word earn its place.

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 parameterless read tool, the description provides the key output (net-change), the source (rlusd_supply_history), and important qualifiers (finalized, proof envelope). Without an output schema, it could specify the return format more explicitly, but the domain-specific terms are sufficiently explained for an agent to invoke correctly.

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?

The tool has zero parameters, so schema coverage is trivially 100%. Per the baseline rule for 0 params, this scores a 4; the description correctly avoids inventing parameters and focuses on the tool's behavior.

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 opens with 'Return the last finalized 24h XRPL net-change from rlusd_supply_history,' which is a specific verb+resource+scope. It clearly distinguishes from siblings like get_rlusd_supply (which likely returns current supply) and get_signed_snapshot.

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 description does not explicitly state when to use this tool versus alternatives, nor does it name sibling tools. However, the specific 'last finalized 24h net-change' phrasing implies its intended use case. With no parameters, usage is straightforward, but there is no explicit comparison to other get_* tools.

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