What is this thing?

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety is covered; the description redundantly says 'Read-only' but adds genuine behavior: ambiguous words are reported as ambiguous, unknown things return the nearest family marked generic, and input tolerates English/Dutch plurals, typos and compounds. It does not describe output shape or latency, keeping it short of a 5.

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?

Front-loaded with the core action and the returned content, then the alternative routing, then input flexibility. It is a long dense sentence-chain, but nearly every clause carries routing or behavioral information; only the trailing 'Read-only' is wasted given annotations.

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 exists, so the description carries the return-value burden, and it does: family, required parts with movement/axis/pivot, size range with source and confidence class, variants, conventions, pitfalls. With one fully documented parameter and clear sibling routing, an agent has everything needed to call and interpret it.

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% and the single schema description already gives examples ('a tractor', 'helikopter'), so the baseline is met by the schema. The description adds value by clarifying accepted input forms (English or Dutch, plurals, typos, compound words, or a freeform description like 'something with wheels and an engine'), which the schema does not.

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?

States a specific verb and resource ('say what a thing is') and enumerates exactly what it returns: family, parts, movement axes, pivots, size range with source and confidence, variants, Godot conventions. It explicitly distinguishes itself from godot_model_lint and godot_model_brief, so the agent can route without opening sibling schemas.

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?

Explicit when-to-use ('before you build or check a 3D model', for full facts) and names alternatives with the condition that selects them: godot_model_lint for the archetype name, godot_model_brief for a short page naming the ready-made kind and spec format. Nothing is left to inference.

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