Choose which reference image to reconstruct

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

Annotations already provide idempotentHint=true and destructiveHint=false, but the description adds meaningful context: it is free and local (no network call, no credits) and that it 'records' which candidate image to use. This goes beyond the structured annotations and helps the agent understand side effects (state change, but idempotent) and cost implications.

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 concise sentences with no fluff. The free/local note is front-loaded, followed by the core action and workflow. Every sentence earns its place, and the structure is immediately scannable.

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 two-parameter selection tool with no output schema, the description is largely complete: it explains the core action, the workflow sequence, and key behavior (free/local). The only gap is the undocumented assetJobId, but given the tool's simplicity and the workflow clarity, a 4 is reasonable.

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 50%: candidateId has a description, assetJobId does not. The description mentions 'candidate image' which indirectly relates to candidateId, but it does not clarify assetJobId at all. The description adds marginal value beyond the schema but fails to compensate for the undocumented parameter, so a 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 states a specific action ('records which candidate image') on a specific resource ('for 3D reconstruction'), and explicitly places it between generate_asset_reference and create_3d_asset. This clearly differentiates it from siblings like generate_reference_variations or create_3d_asset.

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 gives explicit workflow context: 'Call this after looking at the candidates from generate_asset_reference, and before create_3d_asset.' This is clear when-to-use guidance. It does not mention when not to use or list alternative tools, but the workflow sequencing is strong enough for a 4.

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