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

With no annotations provided, the description carries the full burden of disclosing side effects and read-only behavior. 'Current time' implies a non-destructive lookup, but the description does not explicitly state that the tool has no side effects, requires no special permissions, or handles invalid timezone names.

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 brief and front-loaded, but it omits essential information about the misleading parameters and usage context. A concise description should still clarify the tool's scope; this one leaves critical gaps.

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?

The description is incomplete for practical use: it does not explain why url, host, and json parameters are present, does not describe the output format, and does not state how invalid or unrecognized timezone names are handled. Given the confusing parameter list, an agent would struggle to invoke the tool 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?

Although all four parameters have schema descriptions, most are unrelated to the stated purpose. 'url', 'host', and 'json' appear copied from other tools (normalize-url, compatibility, validate-json) and are not explained in the context of timezone lookup. Only 'zone' aligns with the description, and no guidance is given on the other parameters' relevance or expected values.

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 indicates the tool returns the current time for a named IANA timezone, which distinguishes it from the sibling utc-time tool. However, it uses a noun phrase rather than an explicit verb like 'get' or 'retrieve', so the intended action is implied rather than stated.

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 gives no guidance on when to use this tool versus siblings such as utc-time or iana-zones. There is no mention of prerequisites, fallback behavior, or cases where another tool would be more appropriate.

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