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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the output is Markdown, courses are long, and each concept is rendered as a card containing definition, example, caveat and related concepts.

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 tight sentences, front-loaded with the primary purpose and keying parameter. The second sentence about course length and card structure is dense but earns its place as a size warning for the caller.

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 annotations covering safety and a short two-param schema, the description adequately fills the remaining gap by describing return format and content shape in the absence of an output schema. It does not mention truncation or pagination limits, a minor gap given the stated length of courses.

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%, so both slug and language are already documented in the schema with an example and an enum. The description only adds the provenance of the slug ('from list_courses'); it says nothing about language selection, which is fine since the schema handles it.

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 ('the full text of one course as Markdown') plus the keying parameter ('by slug'), which cleanly distinguishes it from list_courses and the other get_* siblings. An agent can tell what it retrieves without opening the schema.

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?

Explicitly routes the agent to list_courses as the source of the slug, which is the main prerequisite for calling this tool. No explicit when-not condition or alternative for retrieving course content in another form, but the context is clear.

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