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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds substantive behavioral detail beyond that: it returns median CZK/m² from realised land-registry sales, sorted most-expensive-first with % difference vs the top locality, and that streets are unsupported. It stops short of noting coverage limits or data recency.

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 trigger condition and followed immediately by the exclusions, which is exactly the right order. The bilingual duplication roughly doubles length, but each half is dense and waste-free.

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 two-parameter read tool with full schema coverage and no output schema, the description supplies the return shape (median CZK/m², ordering, % delta) and all routing rules. Nothing an agent needs to call it correctly is missing.

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 100%, so both parameters are fully documented in the schema (including the 2–8 array and 'Praha N' format). The description reinforces the district-vs-street constraint but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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+resource (compare 2–8 Prague localities) with explicit scope limits (2–8, districts/boroughs, streets not supported) and names the sibling tools it is not. An agent can distinguish it from ceny_bytu_lokalita, top_ctvrti_praha and odhad_ceny_bytu without opening any schema.

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?

Explicit when-to-use (user wants to COMPARE 2–8 specific localities) and when-not-to-use, each with the correct alternative tool and the selecting condition (single locality, citywide ranking, specific apartment with floor area). Nothing is left to inference.

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