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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds real behavioral context beyond that: it is a GET against /api/apartments and returns id and name, telling the agent what shape of data to expect. It stops short of noting pagination or whether the list is account-scoped in size, hence 4.

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?

Three compact sentences, each earning its place: purpose, terminology clarification, usage entry point, and the underlying endpoint. The most actionable guidance (start here) is front-loaded.

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 compensates by stating the returned fields (id and name). For a zero-parameter read-only listing whose safety is declared by annotations, nothing an agent needs to call it correctly 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?

The tool takes zero parameters, which is the baseline-4 case. There are no parameters for the description to clarify, and it correctly implies no filtering is required.

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 every property in the account') and explicitly reconciles the naming ('Smoobu calls them apartments'), which prevents confusion with the sibling smoobu_get_apartment. It also names the returned fields (id and name), so an agent can distinguish this list tool from the single-resource getters.

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?

Says 'Start here to get apartment ids', which gives a clear entry-point condition for using this tool before others. It does not explicitly contrast with smoobu_get_apartment or state when not to use it, so it falls short of the explicit-alternatives 5.

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