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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so the description adds valuable context: it returns a 'compact, actionable shortlist' with a default of 10 available or upcoming rentals. This clarifies the scope and default behavior without contradicting annotations.

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 description is two crisp sentences: the first states the purpose, the second covers default and next step. No redundant words, perfectly front-loaded with the most critical information, and every sentence earns its place.

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?

The tool is complex (11 optional parameters) but the description provides a high-level summary, default behavior, and a pointer to the companion get tool. Since an output schema exists and parameter descriptions are thorough, the description doesn't need to repeat return details. It sufficiently equips an agent to invoke 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?

With 91% schema description coverage, the schema already documents parameters well. The description summarizes the filter dimensions (location, availability, capacity, etc.) which maps to parameters, but adds little beyond what the schema provides. It meets the baseline but doesn't significantly enhance parameter understanding.

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 clearly states the tool returns a compact shortlist of published furnished apartments, filterable by specific criteria (location, availability, capacity, rooms, duration, rent). It distinguishes from the sibling tool rentals.get by explicitly pointing to it for complete details, and the name/title align perfectly with this purpose.

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 explicitly advises calling rentals.get for complete details after receiving the shortlist, establishing a clear workflow. While it doesn't enumerate all alternative tools (e.g., check_availability), the context makes it evident this is the primary search entry point and it gives a specific follow-up action, providing sufficient guidance.

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