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

Annotations already cover read-only/idempotent/non-destructive, and the description adds real behavioral context: the pricing model (test and learning free, certificate paid only after passing), that certificate validity varies by country, and that this tool does not enrol anyone (the person enters their own details at the URL). It also specifies the US default when country is omitted and instructs the agent not to shorten employer_acceptance wording.

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?

Front-loaded with the purpose and the returned fields, then flows into operational guidance and the argument default. The country-code enumeration ('US, CA, GB or UK, NZ, and others') partially duplicates the schema, which is the only wasted phrasing.

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 an output schema present, the field list does not need to be explained in prose, and annotations cover the safety profile. The description still supplies the enrolment flow and country default the structured fields don't convey; only an explicit sibling-routing line is missing.

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% and there is a single optional parameter, so baseline 3 applies. The description restates the expected format and the US-when-omitted default rather than adding new syntax or constraint detail beyond the schema.

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 ('List the online CPR, AED and first aid courses ... for a country') and enumerates exactly what each entry contains (URL, price, length, validity, summary, audience, employer_acceptance). It is clearly distinguishable from get_course, though it never explicitly frames itself against that sibling.

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?

Implied usage is present: it tells the agent to use a country code and to send enrollees to the course URL. However, it gives no explicit when-to-use-vs-alternative guidance (e.g. 'for a single course use get_course', 'for the wording alone use employer_acceptance') beyond referencing employer_acceptance wording in passing.

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