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

No annotations are provided, so the description carries the full burden, and it does: the key is returned only once, must be stored, has a wr_ prefix, is capped at 3 active keys per wallet, and past the daily cap calls fall back to x402. These are non-obvious operational constraints an agent could not infer from the schema.

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?

Front-loads the step and purpose, then constraints, then downstream usage in dense sentences with no filler. Every clause earns its place.

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?

With no output schema and no annotations, the description still covers the return value (wr_... key, single display), storage obligation, rate/limit behavior, and fallback path. Nothing needed to call this correctly and use the result 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?

Schema coverage is 100%, so the baseline is 3. The description goes beyond the schema by clarifying that the signature must be YOUR (caller's) signature and that it signs the message produced by registry_onboarding_message, and that timestamp is the one returned with that message — meaningful provenance the schema fields do not state.

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 ('create' an 'API key') and frames it as 'Step 2' of a multi-step flow, explicitly distinguishing it from Step 1 (registry_onboarding_message). An agent can tell exactly what this does and where it sits in the sequence without opening the 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?

Explicitly states the inputs required and their origin ('wallet, the timestamp and YOUR signature over the message from registry_onboarding_message(action=api_key)'), and names the downstream consumers (registry_search_tools / registry_tool_detail) so the agent knows when to reach for this versus the sibling tools.

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