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

The description frames the tool as an informational guide using 'Explique comment' (explains how), which implies a read-only, non-destructive operation. It details the topics covered but does not explicitly state the response format or that it is a reference document. The guide's French language is implied by the description, but not explicitly stated. Since no annotations are provided, the description carries the full behavioral disclosure burden, and this is largely met.

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. The first sentence enumerates the guide's content, and the second gives usage guidance. There is no filler or redundant information; every phrase adds value.

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 zero-parameter documentation tool, this description fully covers what the tool does and when to use it. The lack of an output schema is acceptable since the guide is informational; the description sufficiently tells the agent what to expect without needing a detailed return format.

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?

The tool has zero parameters, so the schema is trivially complete. The description does not need to explain parameters, and any missing information is not applicable. This aligns with the baseline for zero-parameter tools.

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 explains what the tool does: it provides a guide on writing an app, including data storage locations, persistence patterns, and how to evolve an app without breaking user data. This is specific and distinct from sibling tools (which are actions like publish_app, update_app, etc.), making the purpose unmistakable.

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 explicitly states when to use the tool: 'À lire avant de publier une app qui enregistre quelque chose, et avant tout update_app qui change la structure des données.' It references sibling tools (update_app) for specific scenarios, providing clear timing and alternatives.

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