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

Annotations are all false, providing limited safety information. The description adds valuable context: it is a one-time operation, Supabase Auth verifies ownership, and no financial authorization occurs. This goes beyond the fields and clarifies behavioral expectations.

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?

The description is two sentences, front-loads the main purpose, and adds a meaningful security clarification without redundancy. 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?

With an output schema and sibling tools present, the description covers the essential behavior and safety traits. The only missing piece is an explicit prerequisite like 'call after start_agent_registration', though the schema's message description partially covers this.

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 schema already provides descriptions for message and signature (67% coverage), and the description reinforces the concept of an exact signed challenge. However, challengeId is only described as 'uuid' in the schema and not explained in the description, leaving a gap for that parameter.

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 clearly states a specific verb ('Verify') and resource ('EIP-4361 challenge', 'RigorLoop agent key'), and the phrase 'once' indicates a one-time completion step. It distinguishes itself from sibling start_agent_registration by focusing on verification and key return.

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 implies the tool is used to complete an agent registration flow and includes a helpful security note that the signature does not authorize payment or transfer. It does not explicitly name alternatives or state when not to use it, but the context is clear enough.

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