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

With no annotations, the description must carry the behavioral burden. It discloses the inputs, their defaults, and that the tool 'Returns the current code', which implies a time-rotating, side-effect-free computation. It omits important traits such as whether the code expires with the period, whether any credentials or network are required, and how the `locale` argument affects the result.

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?

Four short sentences with the core action front-loaded and no filler. The input list partly restates the schema, but with 0% schema coverage that restatement is justified rather than redundant.

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 4-parameter tool with no annotations and no output schema, this covers the essentials (input, defaults, return) but leaves `locale` unexplained and gives no detail on the code's time-based validity. It is adequate but has clear gaps.

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 0%, so the description has to compensate. It documents `secret`, `digits` (default 6) and `period` (default 30), which is useful given the bare schema, but it silently drops the `locale` parameter and its en/zh enum, leaving that argument entirely undocumented.

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 names a specific verb and resource ('Generate a TOTP code from a Base32 secret'), so the agent knows exactly what it produces. No sibling tool overlaps with TOTP generation, so sibling differentiation is not needed, but the definition never positions itself against the utility siblings either.

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?

'Use to verify 2FA setup' gives one concrete scenario, which is better than nothing, but there are no when-not conditions and no alternatives offered. Usage is implied rather than scoped.

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