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

Annotations already cover the safety profile (non-readonly, non-destructive, non-idempotent, closed-world). The description adds real value beyond them: no portal login is needed, the returned key is immediately usable in-session, and a test key is distinct from a production op_live_* key. It stops short of saying whether repeated calls mint additional keys or whether the test key expires.

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, front-loaded with the outcome and the returned key prefix, then the production alternative and the ordering hint. No filler or redundant restatement of the tool name.

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 two-parameter registration tool with full schema coverage and an output schema, the description covers the essential context: what is created, what prefix to expect, and the production path. Minor omissions (key lifetime, behavior on repeat calls) are tolerable given the output schema and annotations.

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%, and both parameters already explain their role (name as a label, email for notifications and OTP). The description adds no parameter-level meaning beyond the schema, so the baseline of 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 specific verb and resource ('Create a free test API key') and immediately names the artifact returned (op_test_*). It is trivially distinguishable from siblings like register_webhook or create_formation, which act on different resources.

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?

Gives an explicit trigger ('Call this first if you have no API key yet') and routes the production case elsewhere ('complete email OTP verification via the portal'), so the agent knows both when to call it and when not to.

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