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

Annotations already declare read-only, idempotent, open-world, non-destructive, so the safety profile is covered; the description then adds substantial context beyond that. It discloses the critical semantic that missing onshore data means unknown rather than falling back to the offshore price, that totals are independent of course parts, and that this is a public endpoint returning English natural-language text that preserves sources, conditions and pagination.

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?

Four dense sentences, each carrying distinct information, with the core purpose front-loaded and paging constraints placed after. The trailing clause 'preserving sources, conditions and pagination' is somewhat vague and could be tightened, but nothing is redundant.

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?

With no output schema, the description carries the burden of describing returns and does so at a high level (English natural-language text, sources and conditions preserved, pagination preserved). For a read-only five-parameter tool that is close to sufficient; a brief statement of what a 'packaged study plan' contains or how it differs from a course pathway would close the remaining gap.

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 only 20% — only locale is documented — so the description must compensate, and it largely does. It supplies the pageSize default (5) and maximum (20) and, most importantly, the otherwise undocumented rule that page > 1 requires the original contentVersion, which is essential to correct paging. It does not describe the format or constraints of the required 'course' parameter, leaving one meaningful gap.

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 opens with a specific verb and resource: 'Read complete packaged study plans in study order, with separate offshore and onshore totals.' That is concrete enough for an agent to know it returns packaged plan data with dual pricing. It never names a sibling such as get_course_pathways or get_course, so the boundary between 'packages' and 'pathways' must be inferred.

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?

Usage is implied rather than stated: the agent can infer this is the tool for full packaged plans with offshore/onshore totals, and the pagination rules ('page > 1 requires the original contentVersion') guide correct invocation. There is no explicit when-to-use or when-not-to-use guidance, and no alternative tool is named despite several closely related siblings.

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