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

With no annotations, the description must carry the behavioral burden. It mentions 'WGS84' and 'offline', which are useful traits, but it does not disclose input format expectations, error handling, limitations, or what happens with invalid input. It adds some context beyond the schema but remains thin.

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 a single, efficient sentence that front-loads the purpose and key attributes. Every word adds value, with 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?

For a simple conversion tool with an output schema, the description covers purpose and datum, but omits critical input formatting details and any mention of error cases. The offline and WGS84 notes are helpful, yet the missing parameter specification leaves the tool incomplete for an agent to call 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?

The schema has one parameter 'q' with zero description coverage (0%). The description implies the parameter accepts lat/lon but does not specify the exact format (e.g., 'lat,lon', 'lat lon', order, decimal degrees). Since the schema provides no help, the description fails to fully clarify how to construct the input.

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 explicitly states the conversion from lat/lon to UTM coordinates, specifies the WGS84 datum, and notes offline capability. It uses a clear arrow notation indicating transformation, making the tool's purpose unambiguous and distinguishing it from coordinate-related siblings like geohash or mgrs.

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?

There is no guidance on when to use this tool versus alternatives. With many sibling tools (geohash, mgrs, pluscode, etc.), the description fails to mention any selection criteria, exclusions, or alternative tools for different coordinate systems.

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