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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds real value by declaring that search is free-text rather than fielded, and that the response is identity-only (ids) requiring a follow-up fetch — a meaningful behavioral contract for an agent planning a call sequence.

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 short sentences, zero filler, with the search scope front-loaded ahead of the return contract. It is slightly telegraphic ("ids for fetch" is clipped), which costs a point but keeps it dense and scannable.

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 single-parameter search with no output schema, the definition is functional but thin: no result limits, ranking, pagination, or empty-result behavior. The fetch handoff is covered, but an agent has no picture of what a result set looks like or how to page through it.

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?

There is one required parameter with 0% schema description coverage, so the description must compensate for the gap. It says nothing about query syntax, whether phrases/operators are supported, whether it matches location or free text, or length constraints — the single parameter remains semantically opaque.

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 (free-text search) and resource (Heimster listings and new-build projects). The scope deliberately spans both domains, which implies a cross-cutting search distinct from the narrower search_listings and search_new_builds siblings, though it never names them to make that contrast 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?

"Returns ids for fetch" implies the intended two-step workflow (search, then fetch), which is genuine usage guidance. However, it never states when to prefer this over search_listings or search_new_builds, nor when it is the wrong choice, so the routing decision 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.