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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint, so the safety profile is covered. The description adds genuine extra context by stating that images and owners are NOT returned, which warns the agent it must fall back to another tool for those fields. Pagination behavior is left to the schema's next_page note rather than described here.

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 compact sentences plus the endpoint reference, with the statement of what the tool is and what it returns front-loaded. There is little waste, though the filter-category list partly duplicates the schema and could be trimmed.

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 20-parameter, no-output-schema search tool, the description does reasonable work: it identifies the resource, summarizes the filter set, and clarifies what is and isn't returned. It omits return shape details (pagination, ordering defaults), but the schema covers pagination and the field list partially compensates for the missing output schema.

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 every one of the 20 parameters is already documented in the schema, making 3 the baseline. The description only restates filter categories at a high level and adds no syntax, format, or interaction detail beyond what the structured 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?

The description gives a specific verb and resource ('List or search properties (Objekte / units)') and enumerates the fields returned (address, type, marketing type, rooms, areas, prices, status). It even names the underlying endpoint (GET /units). It stops short of contrasting itself with siblings like the single-property get_property, so differentiation is implicit rather than explicit.

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?

It enumerates the available filter axes (free text, status, tag, project, marketing type, object type, price and area ranges), which implies when the tool is appropriate, but it never states when not to use it or which sibling to prefer for a specific lookup. Usage is inferable rather than guided.

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