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

Annotations already declare readOnly/idempotent/non-destructive, so the first sentence is largely redundant, but 'never signs, submits, or executes a transaction' is a genuinely useful non-obvious guarantee for a tool named 'prepare' — an agent could otherwise reasonably assume prepare also broadcasts.

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, no filler, and the artifact being produced is front-loaded ahead of the safety qualifier. Nothing to cut.

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?

An output schema exists so return values need no explanation, which helps. However, the tool takes a nested object with additionalProperties:false and no documented subfields, and the description does not sketch what a valid request contains — a real gap for a single-param preparation tool.

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% for the single top-level property, so baseline is 3. The description adds only the notion that the payload is a 'bounded authorization'; it does not illuminate the nested input object at all, leaving the agent to supply an opaque request body.

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 gives a specific verb pair (canonicalize, return) and a concrete output artifact (EIP-712 typed data or Solana message) tied to a bounded authorization. It clearly distinguishes itself from a signing tool, though it never names or contrasts the closest siblings (priorseal_accept_authorization, priorseal_prepare_controlled_execution).

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?

It implies the scenario ('for a human-controlled principal to sign') so an agent can infer the prep-then-sign flow, but it gives no explicit when-to-use, no prerequisites, and no guidance on picking this over accept_authorization or get_authorization.

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