App authoring guide

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

Annotations already declare readOnlyHint=true, so the safe read nature is known. The description adds behavioral context by enumerating what the guide contains (contract, tokens, data model, template), making the tool's output predictable. It does not introduce contradictions and offers meaningful detail beyond the structured annotations.

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 punchy sentences: the first delivers an imperative usage directive, the second lists the concrete contents. No filler or redundancy; every word earns its place and the most important instruction is front-loaded.

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 guide tool with one optional enum parameter and no output schema, the description covers the core return value well (contract, tokens, model, template). It does not list the individual chapters (functions, embed, style), but those are enumerated in the schema, so completeness is adequate. Slightly more detail about how the topic parameter alters the output would push it to 5.

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%: the 'topic' parameter is fully documented with an enum and a clear description ('which chapter... Each chapter stands alone'). The tool description does not need to repeat this. It neither adds nor detracts, so the baseline of 3 applies.

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 ('Returns') and names the exact resources delivered: the window.oma API contract, CSS design tokens, data model, and a minimal working app template. It also includes an explicit 'READ THIS FIRST' instruction, clearly distinguishing it as an orientation/guide tool from siblings like get_app or edit_app.

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 opening 'READ THIS FIRST before creating or editing an app' is an explicit when-to-use directive. It signals the tool is a prerequisite step before mutation tools like save_app or edit_app. The description does not list alternatives, but the strong directive makes usage context unambiguous.

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