addMarker

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

Annotations are neutral, but the description adds value by specifying the return format ({ success, data: { entityId }, message? }) and instructing to keep entityId for removeEntity. This provides behavioral context beyond the schema.

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 two sentences, front-loaded with the main purpose, and every word adds value. No fluff or repetition.

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 point marker tool with full schema parameter descriptions, the description covers the essential return format and a follow-up action. It could mention customization options (size, color, label) but those are in schema. Overall adequate.

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 all 7 parameters, so the description does not need to add parameter details. It only mentions entityId in the return, which is not a parameter, so baseline score of 3 is appropriate.

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 'Add a point marker at geographic coordinates,' specifying the verb, resource, and location scope. It distinguishes from sibling tools like addPolyline, addPolygon, and addLabel by focusing on point markers.

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 does not explicitly state when to use this tool versus alternatives like addGeoJsonPrimitive or addLabel. The hint to 'keep entityId for removeEntity' implies a workflow, but no direct comparative guidance is given.

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