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 the timezone (Europe/Berlin), the exact output format (YYYY-MM-DD HH:MM:SS CET/CEST), the optional filter parameters, and the default behavior of returning all 52 entries. This is substantial behavioral context, though it does not explicitly describe the response structure (e.g., whether it returns a list of objects with area identifiers).

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 extremely concise yet information-dense: two sentences that front-load the core purpose and format, then cover filters and default behavior. No filler or redundancy.

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 gives the time format, timezone, filters, and default behavior, but does not clarify the return structure (e.g., a single string vs. a list of objects with area identifiers) or what the '52' entries represent. Without an output schema, this gap could confuse an agent, though referencing get_service_area partially mitigates 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?

The schema has 0% description coverage, so the description must add meaning. It does state that slug, plz, and name are lookup filters, and references get_service_area for their semantics. However, it does not specify formats, valid values, or how filtering works beyond that reference, leaving the agent to infer details from another tool.

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 tool's purpose: it returns the local time in Europe/Berlin to the second, with the exact format given. It also identifies the optional lookup parameters (slug, plz, name) and the default behavior (all 52 results), distinguishing it from sibling tools that handle other resources like contact info, legal pages, or maps.

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 implies usage for retrieving current local time, and references get_service_area for lookup semantics, which helps an agent understand how to filter. However, it does not explicitly state when to prefer this tool over alternatives or provide exclusion criteria. The guidance is implicit rather than explicit.

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