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

With no annotations, the description provides useful behavioral context: the nonce expires in 5 minutes and the flow involves returning a message to sign. It does not explicitly disclose side effects or auth details, but for a nonce request, this is sufficient.

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 three sentences, front-loaded with the action, and every sentence earns its place. No fluff or redundancy.

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 simple nonce-request tool with no output schema or annotations, the description covers the essential context: the step in the verification flow, the expiration behavior, and the relationship to set_wallet. It could mention the return format more explicitly, but that is not critical for invoking 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?

Schema description coverage is 100%, so the baseline is 3. The description does not add any additional meaning to the parameters beyond their schema descriptions, which already cover agent_id, agent_key, and wallet_address adequately.

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 'Request a signing challenge (nonce) for wallet verification,' using a specific verb and resource. It also distinguishes itself from set_wallet by positioning it as step 1, making it easy to differentiate from siblings.

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?

Explicitly states 'call this first, then sign the returned message... and pass the signature to set_wallet,' providing clear when-to-use guidance and naming the alternative/successor tool. This is exactly what the dimension asks for.

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