get_course_module

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the useful point that this avoids a whole-course fetch, but says nothing about behavior for invalid or inaccessible cmids, despite openWorldHint implying access/permission variability.

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?

One sentence with the resource and identifier up front, and the rationale (avoiding whole-course fetch) immediately after. No waste beyond a slightly wordy trailing clause.

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 one-parameter read tool with an output schema, the definition covers purpose, input, and the reason to prefer it over the bulk listing tool. The missing piece is what happens on an unknown or invisible cmid, which would matter given openWorldHint.

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 coverage is 100% and the schema already defines cmid as the course module id. The description adds no format, type, or sourcing guidance beyond 'by its id', so the baseline 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?

States a specific verb and resource: resolve a single course module by its id. It also hints at the contrast with bulk-fetching a course's contents, though it never names get_course_contents explicitly, so it stops short of full sibling differentiation.

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?

Gives clear usage context: use this when you already have the cmid and want to avoid fetching and filtering the whole course. It does not state when not to use it, nor does it name the alternative tool by name.

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