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

Annotations cover safety (readOnlyHint, destructiveHint false, idempotent, openWorld), and the description adds behavioral context beyond them: it's paginated, returns an 'opaque cursor for the next page', and lists what fields are returned. It doesn't discuss rate limits or failure modes, but for a read-only listing tool with full annotation coverage, this is solid.

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?

Front-loaded with the core purpose, then structured with clear 'When to use' and 'Prefer another tool' cues, ending with an example. Reasonably tight, though the parenthetical field list and example slightly lengthen it beyond the minimum needed.

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 paginated read-only list tool with 4 params, full schema coverage, an output schema, and full annotations, the description covers purpose, alternatives, pagination behavior, and an example. Nothing an agent needs to invoke it correctly is missing.

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 the schema already fully documents each parameter (peer, limit, marker, address). The description provides an example invocation with address but adds no additional parameter syntax or semantics beyond what the schema states. Baseline 3 is appropriate.

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+resource+scope: 'One page of an account's trust lines, with an opaque cursor for the next page.' It also names what trust lines contain (balances, limits, freeze and authorization flags) and distinguishes from siblings by explicitly naming the alternatives (summary endpoint, token endpoint).

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?

Explicit 'When to use' and 'Prefer another tool' sections name the alternative tools and the conditions for choosing them: '/v1/xrpl/account/{address}/summary' for a quick capped overview, token endpoint for issued totals. Nothing is left to inference.

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