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

With no annotations, the description must fully disclose behavior. It states it returns delta hours and local times, but does not mention that inputs are limited to a fixed list of cities (from the schema) nor any read-only or destructive nature. Essential behavioral details are missing.

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 concise, consisting of two sentences plus a reference to list_bundles. Every sentence adds context, though the reference to list_bundles may be slightly tangential. It is front-loaded with the core purpose.

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?

Given the simple input schema (2 enum parameters) and existence of an output schema, the description adequately covers the return format. However, it fails to note that inputs are limited to the provided city list, which is a critical constraint for an agent to correctly invoke the tool.

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 coverage is 100% with descriptions for each parameter ('First city', 'Second city'). The description adds that these represent timezones and explains their role in the computation, but does not clarify that the enum values are specific city names rather than generic timezone identifiers.

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 computes time difference between two timezones for international meetings. It is specific about the resource (time difference) and verb (compute). However, it does not differentiate from sibling tools like calculate_time_difference or calculate_timezone_convert, which may have similar functionality.

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 suggests using the tool for international meetings and references list_bundles for related calculators. However, it does not provide explicit guidance on when not to use this tool versus alternatives, nor does it mention the input constraints (only specific cities are supported).

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