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

The annotations declare that the tool mutates state, is idempotent, and is non-destructive; the description restates idempotency, which adds little. However, the description adds genuinely new behavior: header-authenticated callers are exempt, a wallet key is not issued while custody is paused, and the call gates other tools. It does not explain what happens if the key was not actually persisted, which is the key failure mode.

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?

It is dense and front-loaded: the core action comes first, followed by the prerequisite, then the exemption, and finally the custody caveat. Every sentence carries information, although the parenthetical about the wallet rebuild is tangential to actually calling the tool.

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 not be described. The description covers prerequisites, exemptions, and a platform-state caveat, which is strong for a zero-param tool. It is slightly under-specified on what 'upgraded guest session' means and on the failure mode when the key was not persisted.

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?

There are zero parameters: the owner is derived from the authenticated principal, as the input schema states. With no arguments, the description's job is minimal, and the baseline of 4 applies; it does not add surfacing detail beyond the schema.

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 states a specific verb and resource: it confirms that the api_key/owner_key shown once at register has been persisted. It names register as the source and distinguishes itself from sibling tools such as hire_and_execute and escrow, which depend on it. The only slight weakness is that 'confirm' could be read as verification rather than an attestation flag, but context makes it clear.

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 states exactly when the tool is needed (on an upgraded guest session, before money tools) and names those tools. It also states when the tool is not needed, namely for header-authenticated callers, and it gives a clear condition for choosing it.

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