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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: the wallet key must be set as an environment variable and payments flow through x402 in USDG. It does not describe the response shape, but for a help/explanation tool that is a minor gap.

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 purpose and closing with the invocation trigger; the middle segment is information-dense but every clause maps to a distinct setup topic. Slightly packed, 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?

For a parameterless, read-only explanatory tool with no output schema, the description covers what an agent needs: what is explained, when to invoke it, and the server/key prerequisites. Only the returned content format is left implicit.

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 takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies.

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 ('Explain how to use Priors from an MCP client') and enumerates the exact topics covered: the hosted server URL, the local @priors/mcp server with wallet key, and x402 payment in USDG. This clearly separates it from action siblings like request_borrow or pool_stats.

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?

Gives an explicit trigger: 'Call this when the user wants to pay, borrow, repay, or set Priors up.' That covers the main use contexts well, but it does not name sibling tools (e.g., request_borrow/request_repay) or state when not to call it.

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