get_datetime

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

No annotations are supplied, so the description carries the full burden. It signals a live, non-mutating read by saying 'current', but it does not disclose the return format (ISO 8601? epoch?), precision, or whether an invalid timezone errors or silently falls back to UTC — the last being a real behavioral question given the phrasing 'Defaults to UTC' in the schema.

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?

One sentence, front-loaded with the core action, with the optional qualifier trailing. Nothing is wasted and nothing essential 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?

For a one-optional-parameter, side-effect-free tool with a fully documented schema, the description is nearly sufficient. The single remaining gap is the return format, which no output schema covers, so the description could have stated it.

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 the single parameter is fully documented in the schema including an IANA example and the UTC default. The description only restates the optionality, adding no syntax or edge-case meaning beyond 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 ('Get the current date and time') plus the optional scope ('specific timezone'). The intent is unambiguous and no sibling tool in the list offers datetime functionality, so no differentiation is needed. Not a 5 only because it is a very simple, near-tautological statement of a self-evident operation.

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?

Implies usage (call it when you need the current time, pass a timezone when you need local time) but provides no explicit when-to-use framing, no guidance on what to do if the timezone is unknown, and no alternatives since none exist. Adequate but minimal.

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