addModel

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

Annotations are all false (readOnlyHint, openWorldHint, etc.) and provide no safety profile, so the description carries the full burden. It discloses the return structure ('Returns { success: boolean, ... }'), but since an output schema exists, this may be redundant. There is no mention of side effects (e.g., whether the model replaces an existing one), unit conventions beyond what's in the schema, or rate limiting. No contradictions, but little added behavioral insight.

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 sentence with a clear verb and object, followed by a terse return-type note. Every word earns its place, and the information is front-loaded with the action. No fluff 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 tool with 10 parameters, the description is minimal but acceptable given the full parameter documentation in the schema and the existence of an output schema. However, it lacks higher-level context such as what 'add' implies (e.g., does it create a new entity each time or replace one?), and it does not hint at parameter interactions (e.g., heading/pitch/roll relationships). It is adequate for simple use cases but not rich enough for complex scenarios.

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 100%, with each parameter having a description (e.g., 'Heading angle (degrees), 0=North'). The description adds no additional parameter context, so it does not need to compensate. Per the rubric, a baseline of 3 applies when schema coverage is >80%.

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 uses a specific verb ('Add') and a specific resource ('glTF or GLB model') along with the spatial context ('at geographic coordinates'). This clearly distinguishes it from siblings like addMarker or addPolygon, which serve different entity types. The phrase 'glTF or GLB' unambiguously conveys the 3D model use case.

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?

Usage is implied through the terms 'glTF or GLB model' and 'geographic coordinates', suggesting this tool is for placing 3D models in a 3D scene. However, there is no explicit mention of when to choose this over alternatives like addGeoJsonLayer or addLabel, nor any exclusions or prerequisites (e.g., needing a specific tile format). The guidance is implicit rather than explicit.

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