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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description restates the one-shot credential warning that the schema already carries, adding little new behavioral context (e.g. what the returned identity grants, or handle permanence). With annotations carrying the load, this sits at a baseline 3.

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 short sentences with zero waste, and the core action is front-loaded ahead of the caution. Nothing needs trimming.

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 tool with 8 parameters including a nested metadata object, no output schema, and a one-way credential, the description is thin. It omits what the call returns, what the created identity can subsequently do, and handle permanence/uniqueness behavior — an agent must infer all of that from the schema.

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% across all 8 parameters, and each parameter (handle pattern, op_key idempotency, credential format) is fully documented in the schema. The description adds no parameter-level meaning, so baseline 3 applies.

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 concrete verb+outcome: 'Create a persistent identity from a credential you generate.' An agent can tell this is the agent-registration step rather than a credential-issuance step. It does not, however, explicitly name or distinguish itself from nearby siblings like create_credential, recover_credential, or update_agent.

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 only guidance is the operational warning 'Store the credential before you send it.' There is no when-to-use vs alternative framing (e.g. vs create_credential, or before/after other onboarding calls) and no prerequisites or ordering context beyond that single caution.

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