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

Even though annotations already mark the tool as read-only and idempotent, the description adds substantial behavior: it details error responses (course_content_unavailable with a list of readable courses, course_not_found) and enumerates the exact return fields including the sha256 and character length of module text. This goes beyond the annotation signal.

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 front-loaded with the purpose, followed by return details, then edge-case behavior. Every sentence contributes distinct information with no redundancy or filler. The long enumeration is justified by the need to specify stable identifiers for downstream use.

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 single-parameter, read-only, idempotent tool with full schema coverage and an output schema, the description is complete. It covers the main use case, return contents, prerequisite courses, and both error scenarios. Nothing essential is missing for calling the tool correctly.

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 only parameter, slug, is fully described in the schema ('exactly as returned by listCourses, e.g. seo-geo'). The tool description does not add any extra meaning about the parameter, so the high schema coverage 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 starts with a specific verb and resource: 'get the reading order of a course and the identifiers needed by getModuleContent.' This clearly distinguishes it from siblings like getCourseDetails and getModuleContent. The extended return value list further clarifies the tool's role as a module-list provider.

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?

It explicitly says 'Use to get the reading order...' and notes that only courses marked contentAvailable in getCatalogManifest have modules, which is a clear precondition. It does not explicitly name an alternative for other course metadata, so it stops short of a full when-not-to-use statement.

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