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

Goes well beyond the annotations: message is EIP-191 personal_sign and valid only 10 minutes, the signer is recovered server-side, and refusal cases are enumerated (stale/foreign signature, wallet already used by another principal, public key, already registered on chain). It also discloses the auth requirement ('behind the second factor') and the recovery path for a lost wallet via support, which annotations (readOnly=false, idempotent=true, destructive=false) do not cover.

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?

Purpose is front-loaded, but the prose is a dense run-on stuffed with parentheticals and internal vocabulary; the refusal list and the current-wallet exception are packed into single sentences that are hard to scan. Most content earns its place, but presentation could be tightened into ordered steps.

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 state-changing, two-phase signing tool with no output schema, the description covers the handshake, the returned must_sign/current_wallet signal, failure modes and auth. The only real gap is what the second call returns on success and whether the link is reversible.

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%, so the baseline is 3; the description earns above that by tying parameters into a sequence — signed_at comes from the first call, signature_hex must cover that message, and current_signature_hex is only required when must_sign said so. It clarifies the dependency between parameters that the flat schema cannot express.

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: make a wallet the venue's payout wallet for a principal, and even pins its place in a flow ('S1 step 4'). An agent can tell it is a linking/registration action, though jargon like 'the deck's house wallet' and 'the identity door' adds decoding cost and no sibling is named for contrast.

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 two-call protocol is spelled out: call with no arguments to get the message and signed_at, then call again with wallet_hex, signed_at and signature_hex. It also names the conditional path (when the first call returns must_sign, the current wallet co-signs and you pass current_signature_hex). No explicit when-not or alternative sibling is given.

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