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 the ordering behavior ('ordered by sort_order') and the domain relationship ('Modules group lessons; a course has 1..N modules'), which are useful. However, it does not mention safety (e.g., read-only), auth requirements, errors, or pagination, leaving some behavioral traits undisclosed.

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 extremely concise: two sentences, no fluff, and front-loaded with the purpose. Every phrase adds value—'List modules (sections)' defines what, 'ordered by sort_order' adds behavioral detail, and the second sentence provides domain context. This is an exemplary concise structure.

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 one-parameter list tool, the description covers the core purpose and ordering. However, there is no output schema, so the description should explain return values but does not mention what the module list contains (e.g., fields, pagination). The parameter semantics are also weak. The description provides enough for basic understanding but leaves gaps in expected output and parameter handling.

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 schema has 0% description coverage, and the description does not explain the course_id parameter beyond saying 'of a course.' It does not name course_id or add any detail about its format, purpose, or constraints, leaving the agent to infer the mapping from the tool name alone. This is insufficient compensation for the schema's lack of description.

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 states the tool's function: 'List modules (sections) of a course, ordered by sort_order.' It uses a specific verb ('List') and resource ('modules (sections) of a course'), and adds the ordering detail. It also distinguishes from siblings like list_course_lessons by explaining that modules group lessons, making the purpose unambiguous.

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 implies usage by stating that modules group lessons and a course has 1..N modules, which helps an agent understand when to use this tool. However, it does not explicitly mention alternatives (e.g., list_course_lessons, get_course_structure) or provide when-not-to-use guidance, so the usage context is only implied rather than fully explicit.

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