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

With no annotations provided, the description carries the full burden. It discloses one behavioral trait: 'sort_order is optional — server auto-appends if omitted.' This is useful, but it omits other important behaviors such as return values, whether the course must exist, and any side effects on existing modules. Moderate transparency.

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, front-loaded with the main action. Every word earns its place, and it is appropriately sized for a simple create operation.

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 basic create tool with 3 parameters and no output schema, the description is adequate: it states the purpose and the key optional behavior. However, it lacks details on what the tool returns, whether the course_id must reference an existing course, and how this relates to other module-focused tools. Complete enough for selection but not for full invocation context.

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 description adds semantic meaning for sort_order ('server auto-appends if omitted'), which the schema alone does not convey. However, it does not explain the meaning or format of course_id or title beyond their names, and schema description coverage is low at 0%. It partially compensates but leaves gaps.

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 'Add a module to a course' uses a specific verb (add) and resource (module to a course), clearly distinguishing it from sibling tools like create_lesson or create_course. It is unambiguous about the operation.

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 provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., course must exist), nor does it contrast with creating lessons or other components. The usage context is only implied by the verb 'add'.

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