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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds nothing beyond that: no note on error behavior for a missing slug, no auth requirements, and no return shape. The endpoint reference (GET /v2/courses/{id}) is a minor signal but largely restates the read-only nature already annotated.

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?

Two terse sentences with the operation front-loaded and no padding. The trailing API endpoint reference is mildly redundant but costs almost nothing.

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 lookup with its safety profile carried by annotations and its parameter documented by the schema, this is largely sufficient. The one modest gap is that with no output schema, nothing hints at what a course object contains.

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 100% with a single required parameter, so the schema already documents that course_id is the slug with an example. The description's 'by id (its slug)' is redundant with that, so it earns no credit above the baseline.

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?

States a specific verb (Fetch) and resource (one course) and singles out the singular scope by id/slug, which naturally separates it from learnworlds_list_courses. It does not name a competing sibling explicitly, but the scope is 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?

Usage is only implied: the agent can infer this is the single-record lookup versus the list tool, but there is no explicit when-to-use or when-not-to-use guidance, and no mention of how it relates to learnworlds_get_course_contents or learnworlds_get_course_analytics.

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