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

With no annotations provided, the description carries the behavioral burden and does well: it names the data sources (BFS vacancy, rent, ZKB market data), the score range, and that it suggests alternative regions. It also implies this tool only checks chances and that registration happens separately via join_tenant_pool, which is useful side-effect context.

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?

Two sentences, front-loaded with the purpose, and every clause adds value: what it does, what it uses, the score range, an example, and the next step. No filler or redundancy.

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 tool with 10 parameters and no output schema, the description conveys the core outcome, example input, data provenance, and follow-up action. It does not detail the response structure beyond the 0–100 score and alternatives, but that is arguably sufficient for selecting and invoking the tool 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 description coverage is 90%, so the schema already documents the parameters. The description adds contextual meaning by linking the query example to a 'search profile', but it does not explain individual parameters beyond the schema baseline.

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 action ('rates chances'), a precise resource (rental market chances from a search profile), and a concrete output (tenant score 0–100 plus alternative region suggestions). This clearly distinguishes it from sibling listing, FAQ, and pool tools.

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?

Provides an explicit example query ('how are my chances of finding a 3.5-room flat in Zürich for 2200') and a follow-up action via join_tenant_pool. It does not explicitly state when not to use it or name alternatives, but the context is clear enough for an agent to select it.

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