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

With no annotations provided, the description carries the full burden. It discloses that the code is computed in-memory only, never stored or logged, requires no API key, is free, and is not sent anywhere. These are the key behavioral facts an agent needs when deciding to call this tool.

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 English portion is well-structured and front-loaded with purpose, then behavior, then usage guidance. Some redundancy exists because the same content is repeated in Vietnamese, but that bilingual repetition can serve a broader user base without harming clarity.

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, no-output-schema tool, this description is complete. It explains the input, output, privacy behavior, alternative tool, and necessary conditions, so an agent has everything needed to call it correctly.

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 documents the secret parameter 100%, including that spaces are allowed. The description adds only 'requires a valid Base32 secret,' which is useful but not a major semantic addition beyond the structured schema.

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 starts with a specific verb and resource: 'Generate the current 2FA/TOTP code (6 digits) from a Base32 secret key (Google Authenticator style).' It clearly identifies the output format and input type, and the 'PREFER INSTEAD' clause distinguishes it from get_mail_code.

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?

WHEN TO USE gives a concrete condition: the user has an authenticator secret key and needs the live TOTP code now. PREFER INSTEAD explicitly names get_mail_code for email OTP codes, so an agent can route between the two tools without ambiguity.

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