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

Annotations indicate read-only, idempotent, non-destructive behavior. The description adds that results include a source_url when available and the 50-target limit. No contradictions, but no further details on error handling or rate limits.

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?

Two sentences, front-loaded with core purpose, no redundancy. Every sentence adds value.

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?

Covers the main use cases and constraints (limit, source URL). But it lacks guidance on what happens if both 'utc' and 'from' are provided, and there is no output schema to describe the return format beyond 'local time'.

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 high (67%). The description adds meaning by clarifying that 'utc' is read as UTC if no zone designator and that 'from.location' requires exactly one identifier. These are useful but not critical beyond the 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 clearly states the tool's function: convert a given time (UTC instant or wall time in a source location) to local times for up to 50 target locations. This distinguishes it from siblings like get_current_time (which returns current time) and time_by_coordinates (likely single location).

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 specifies when to use the tool (given a UTC instant or wall time) and mentions the 50-location limit. However, it does not explicitly advise when not to use it or compare to sibling tools like search_cities or dst_transitions.

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