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

Annotations already establish readOnly, idempotent, openWorld, and non-destructive behavior. The description adds meaningful context beyond those annotations by disclosing that the inventory includes test records, that the result is not a market valuation, and that geographic filters describe a search area rather than a user's location. This is valuable behavioral caveat information without contradicting the 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 three sentences with no filler. It front-loads the primary usage trigger, then adds market-specific guidance and two important caveats. Every sentence earns its place, and the overall length is appropriate for the tool's complexity.

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 description covers the core purpose, a key geographic convention, and important data-quality caveats. However, with 24 optional parameters and little schema documentation, an agent would benefit from more guidance on how filters relate to one another and what differentiates this count from search_properties. The output schema helps, but the parameter surface is large enough that the description feels slightly incomplete.

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 only 4% across 24 parameters, so the description carries a heavy burden to explain parameter meaning. It adds only two relevant hints: targetMarket RS for Serbia and that geographic filters describe a search area. The remaining 22 parameters, including nested objects like bbox, radius, and polygon, are left entirely to the schema or inference.

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 ('count') and resource ('active listings on nekretninenaprodaju.rs'), and clarifies it applies when the user asks 'how many' listings match explicit filters. This clearly distinguishes it from sibling tools like search_properties or compare_properties, which would return listings or comparisons rather than counts.

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?

The description opens with an explicit trigger condition: use when the user asks how many active listings match explicit filters. It also gives practical guidance such as using targetMarket RS for Serbia and not requesting user GPS or home addresses. It does not explicitly name sibling tools or state when not to use this tool, so it stops short of a 5.

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