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

Annotations already provide idempotent, read-only, and destructive hints. The description adds useful context: it is a prerequisite gate, applies only to upgraded guest sessions, and is unnecessary for header-authenticated callers. The performative verb 'Confirm' could suggest a read-only check, but readOnlyHint=false clarifies it is a state-changing acknowledgment.

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?

Three short sentences deliver the purpose, the usage condition, and the idempotence/auth exception with no filler. The most important scoping information is front-loaded.

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 zero-parameter tool with an output schema and annotations, the description covers the source of the keys, when the tool is required, which tools depend on it, and who can skip it. Nothing essential to deciding whether or how to call it is missing.

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, so the schema needs no additional explanation. The description adds the contextual note that the keys came from register, but no parameter-level semantics are required beyond the schema's statement that the owner is derived from the authenticated principal.

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 names a specific verb ('Confirm you have persisted') and a precise resource (the once-shown api_key / owner_key / wallet_private_key from register). It also distinguishes the tool from register and the downstream money tools by framing it as a required prerequisite.

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 the exact condition for use ('Required on an upgraded guest session before money tools') and names the downstream tools it gates. It also gives an explicit exclusion ('header-authenticated callers do not need this'), leaving little ambiguity about when to invoke it.

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