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

readOnlyHint=true already tells the agent this is a safe read. The description adds genuine value by enumerating the record contents (fees, caveats, resident rules, sources), but says nothing about behavior when the slug is unknown or whether the record can be partial — a gap, though modest given the read-only annotation.

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?

A single tight sentence with the key (slug) and payload (fields) front-loaded; nothing is wasted. The parenthetical field list is informative rather than filler.

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-param read tool with no output schema, the description gives a rough sense of the returned record but omits error behavior for an invalid slug and any note on where slugs come from. Adequate but with clear gaps.

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 0% and there is one required parameter, so the description must carry the load. It identifies the parameter's nature ('slug') but adds no format, example, or source guidance (e.g., where to get a valid slug), leaving the schema's bare 'type: string' largely unenriched.

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 retrieval action ('full record for one course') plus the lookup key ('by slug'), which clearly distinguishes it from search_courses (plural, list) and get_booking_link (different resource). It stops short of explicitly naming those siblings, but the verb+resource 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?

No explicit when-to-use guidance or mention of alternatives. The phrase 'by slug' hints that a slug must first be obtained (presumably from search_courses), but the description never says this or explains when to prefer this tool over the sibling lookup.

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