create_spatial_anchor

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

Description adds persistence and real-world positioning beyond the readOnlyHint annotation. However, it does not disclose error behavior on duplicate names, side effects, or required settings.

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?

Two succinct sentences with no wasted words. Could be more structured but is efficient.

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?

No output schema, no mention of return value. Lacks behavioral context for 8 parameters, such as what happens if anchorName already exists or if attachToPlane fails.

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%, so parameters are documented. Description provides a high-level summary but adds minimal detail beyond what's in the schema.

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 action (creates), resource (spatial anchor), and options (specified position or detected plane). It distinguishes from sibling tools like 'manage_spatial_anchors' which handle existing anchors.

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?

Implied usage for creation, but no explicit guidance on when to use this vs alternatives (e.g., manage_spatial_anchors). Missing prerequisites like plane detection being enabled for attachToPlane.

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