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

Annotations already declare this is a non-read-only, non-destructive write. The description adds genuinely useful behavior beyond that: the key is "shown only once," flagging that the value is unrecoverable if not captured. It does not mention rate limits, name-collision handling, or any auth prerequisite, so it stops short of full disclosure.

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?

A single sentence with no filler, front-loading the action and then the critical return-value caveat. Nothing is wasted and nothing important is buried.

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, the description usefully covers what comes back (the key) and its one-time nature, which is the most important thing an agent must know here. It leaves unaddressed only edge cases like name uniqueness failure, which the schema partially signals.

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%, so both parameters (name, ref) are fully documented in the schema itself. The description only loosely gestures at "a name you choose" and says nothing about the optional ref tag, so it does not add meaning over the schema. 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 specific verb and resource ("Creates your account") and adds a concrete outcome ("returns your key"). No sibling tool overlaps with account creation, so the agent can place it instantly.

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?

Implicitly tells the agent this is the entry point for a new account, but gives no explicit condition such as "call before anything else" or any exclusion (e.g. what to do if you already hold a key). No alternative is named, though none exists among the siblings.

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