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

Annotations declare readOnlyHint=false and idempotentHint=false, which the description reinforces by describing a fresh, transient artifact rather than a pure read. It adds real behavioral detail the annotations cannot convey: a 30-minute TTL, the signing standard (EIP-191), and the organization API key requirement. It does not say whether re-calling invalidates prior challenges, so it is not fully transparent.

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?

A single compact sentence with the step number and purpose front-loaded, followed by the signing format, TTL, and auth requirement. Every clause adds information; nothing is redundant with the title.

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 one-parameter tool with no output schema, the description conveys the essential contract: a message is returned, it must be signed with the given wallet, and it expires in 30 minutes. It could go one step further and tell the agent to pass the signed message to kya_bind_wallet, but the flow is largely reconstructable.

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% and the single parameter 'address' is documented as '0x wallet address your agent controls'. The description only echoes this with 'with that wallet', adding no format, network, or validation detail beyond the schema. Baseline 3 applies when the schema carries the full parameter burden.

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 — 'get a message to sign with that wallet' — plus the exact cryptographic standard (EIP-191 personal_sign) and the framing 'Step 1 of binding a wallet to your Privi Passport'. That framing cleanly separates it from the adjacent kya_bind_wallet sibling without opening either schema.

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 clear context: this is the first step in the wallet-binding flow, it requires the organization API key, and the output is only valid for 30 minutes. It falls short of explicitly naming kya_bind_wallet as the mandatory follow-up step, so the agent must infer the sequencing from 'Step 1'.

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