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

The description adds significant behavioral context beyond annotations: it notes that new codes are returned only once and that old ones are invalidated. This aligns with the destructiveHint=true annotation and provides crucial information for safe invocation. No contradiction with annotations.

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?

The description is two efficient sentences: the first states the main action and key behavioral trait (once-only return), the second lists requirements and errors. No wasted words, front-loads the primary purpose.

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 single-parameter tool with an existing output schema and annotations, the description covers purpose, requirement, errors, and a behavioral warning. Nothing essential 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?

The input schema already describes the 'code' parameter in detail (TOTP or recovery code). The description does not add new semantic information beyond what the schema provides. Baseline 3 is appropriate given 100% schema coverage.

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 clearly states the action ('Replace your recovery codes'), the resource ('recovery codes'), and key distinction from siblings: it generates a fresh set and invalidates old ones. It distinguishes itself from other 2FA tools (colony_2fa_enroll, colony_2fa_disable, etc.) by focusing specifically on regeneration.

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 description explicitly requires a valid current TOTP or recovery code as input, and lists potential errors. While it doesn't explicitly state when to use this tool versus alternatives, the sibling set is small and the purpose is clear enough. A minor improvement would be to suggest scenarios (e.g., lost codes).

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