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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the closing "This tool only reads" is largely redundant. The description does add real behavioral context beyond the annotations: prices are one-time, GST-inclusive for Australian customers, paid designer prices come from a cached catalogue, and a live-price failure degrades to a "see the course page" placeholder rather than an error.

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?

The return fields are front-loaded in the first sentence and the pricing caveats follow in a logical order (currency, GST, cache source, fallback). Dense but each sentence carries distinct information, with only the "only reads" line being expendable.

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 full burden of describing return values, and it does so field-by-field plus explains the degraded-price fallback. For a zero-parameter read-only listing tool, an agent has everything needed to call it and interpret the result.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. The description uses that space instead to explain the shape and provenance of the returned data.

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+resource ("List every Agentic Design School course") and enumerates the returned fields, so the agent knows exactly what it retrieves. It does not explicitly name the alternatives (get_course for a single course, create_checkout_link for purchasing), so sibling differentiation is only implied by the word "every".

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: an agent can infer this is the catalogue-browsing tool and that get_course is for a single item, but the description never says when to prefer this over get_course or create_checkout_link. No prerequisites or exclusions are given.

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