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

Annotations already declare the operation read-only, idempotent, non-destructive, and closed-world, so the description does not need to prove safety. It meaningfully adds that only launched countries are listed, the current release covers home records and move reports, and provider listings/prices are absent.

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 main catalog purpose is front-loaded, and most sentences add useful scope or limitations. The middle release/job-request context is somewhat tangential but helps prevent wrong expectations.

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-only catalog with annotations and no output schema, the description supplies the missing return-field and scope context. It is complete enough for an agent to call correctly.

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%, with country already documented as an optional ISO alpha-2 code and omission meaning all launched countries. The description adds the business constraint that only launched countries appear, but does not add syntax or filtering behavior 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?

The description states a specific verb/resource (list the ONZIP home-services catalog), names the fields returned, and scopes it to launched countries. It does not explicitly contrast with the sibling onzip_get_deadline_rules, so it is clear but not fully disambiguated from siblings.

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?

It gives useful boundaries—unlaunched countries are omitted, job requests are not open, and no provider listings/prices exist—but never says when to choose this tool over onzip_get_deadline_rules or other siblings. Usage is implied rather than explicitly routed.

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