measure

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

Annotations indicate the tool is not read-only, not destructive, and not idempotent. The description adds that it optionally displays results on the map, implying a potential state change. However, it does not disclose what exactly is displayed or whether the display is temporary, nor does it address authorization 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?

The description is a single, front-loaded sentence with no wasted words. It efficiently conveys the core purpose and key features (coordinate-based, optional map display).

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 lacks critical details: it does not explain the return value (e.g., numeric distance/area), the order of coordinates (lon, lat implied but not stated), or the behavior of the 'showOnMap' option. Given the absence of an output schema, these gaps hinder an agent from fully understanding how to use 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?

All five parameters have descriptions in the input schema (100% coverage). The description adds no additional semantic meaning beyond what the schema provides, e.g., confirming coordinate-based calculation. This meets the baseline for schema coverage.

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 what the tool does: 'Measure distance or area (coordinate-based calculation, optionally displayed on map)'. It uses specific verbs and resources, and the purpose is unambiguous. It differentiates from sibling tools like addMarker or queryEntities, which serve different functions.

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. The description only states what it does, without mentioning when not to use it or providing comparisons to sibling tools like getView or zoomToExtent.

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