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

Annotations already declare readOnlyHint=true and destructiveHint=false, establishing the safety profile. The description adds meaningful behavioral context: data is source-dated, reflects live active listings only, and is descriptive rather than analytical. This goes beyond the annotations by clarifying the nature and limitations of the returned data, which is valuable for correct interpretation.

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 sentences, front-loaded with the core purpose and followed by a concise exclusion list. Every word earns its place; there is no fluff or redundant information. Perfectly sized for an agent to quickly parse.

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 has an output schema, so return-value details need not be in the description. The description covers the data source, aggregation type, property type, and explicit exclusions, which is comprehensive for a read-only aggregate tool. It doesn't detail the index computation method, but that is likely covered by the output schema or supplemental documentation. Given the simplicity and existing annotations, this is nearly complete.

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 50% (only 'type' has a description, 'city' does not). The description adds some semantic meaning by connecting 'sale or long-term-rent' to the type parameter and implying the aggregation scope, but it does not explain the city parameter or clarify default behavior when parameters are omitted. The enums are self-explanatory, but the description does not fully compensate for the schema gap.

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 ('Returns') and resource ('source-dated aggregates of live active Evlek sale or long-term-rent asking prices'). It clearly distinguishes itself from individual listing tools by emphasizing it provides aggregate asking-price data, and it further differentiates itself from valuation/forecast tools by explicitly stating what it is NOT. This is more than sufficient to set it apart from the listed 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?

The description provides clear context on what data is included (live active asking prices) and explicitly excludes completed transactions, valuations, forecasts, and investment recommendations. While it does not name sibling tools like get_yield_estimate or search_listings as alternatives, the exclusions strongly imply when this tool should and shouldn't be used. Lacks explicit 'when to use' guidance but has effective 'when not to use' statements.

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