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

Annotations already establish readOnly/idempotent/non-destructive, so the description is free to add what they cannot: the data provenance (Greca House's own listings' ASKING prices, a dated snapshot, reported with sample sizes) and the explicit caveat that it is not a market index. It also warns the agent not to inject remembered 'current market' figures, which is actionable behavioral guidance beyond any structured field.

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?

Front-loaded with the triggering use case and the guidance sentences each earn their place. However, the provenance point is stated twice in near-identical wording ('Answers from Greca House's dated research snapshot of its own listings' asking prices...' followed by 'A dated snapshot of Greca House's own listings' ASKING prices...'), which is real duplication.

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 an output schema present, return values need not be explained, and annotations cover the safety profile, so the remaining burden is scope and source. The description handles both plus its limitations, but never states how old the 'dated snapshot' is or whether sample sizes can be zero, leaving the agent unable to judge staleness or reliability.

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 67%: areas and language are described in the schema, but budget_eur has no schema description. The description compensates by explaining what budget_eur means semantically (it answers what a given budget buys) and by giving example values, which is more than the schema provides.

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 ('compare asking prices per square metre between Greek areas') and two concrete query shapes: area-vs-area and budget-vs-area. It also explicitly distinguishes itself from a whole-market transaction-price index, so an agent can tell it apart from get_greece_market_research and the listing-search 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?

Gives explicit when-to-use triggers (Kolonaki vs Glyfada, or 'what does €250k/€400k/€800k buy') and an explicit when-not list: forecasts, predicted appreciation, next-year growth, time-series trends, whole-market future prices. Alternatives are not named by tool name, but the exclusion categories route the agent unambiguously away from this tool for those questions.

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