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

Annotations already declare readOnlyHint=true and idempotentHint=true; the description adds crucial behavior beyond them — the tool only returns a link, the MCP does not build or broadcast the transaction, and completion happens in the browser with a wallet signature. That resolves the non-obvious async/out-of-band flow.

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 action and the critical browser-signing caveat up front; trigger phrases and ownership requirement follow efficiently. Slightly dense but every sentence earns 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 single-param read-only tool with no output schema, the description covers what an agent must know: what it returns (a link), that signing happens outside the MCP, and the ownership precondition. Nothing material 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 coverage is 100% and documents the single domain parameter with an example, so the baseline is 3; the description adds the owning-wallet precondition and reinforces the domain target, giving a bit of extra meaning.

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 states a specific action (get a link to set a domain as primary) and clarifies the actual sign/broadcast happens elsewhere. It is clearly distinct from siblings like register_domain or resolve_address.

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 gives explicit trigger phrases ('make X.xrp my primary', 'set X.xrpfi as my main domain') and a precondition (wallet must already own the domain), so the agent knows exactly when to pick this tool.

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