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

With no annotations, the description must disclose behavioral traits, and it does convey the core calculation (perimeter formula) and output (length plus off-the-shelf size). However, it claims to cover only 'tilt-and-turn and roof windows' while the schema includes 'kipp' (tilt-only) as the default type, which is an incomplete and potentially misleading coverage statement. This gap in transparency is significant for a tool with no annotations.

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 concise, with two sentences in German and English that pack all essential information: purpose, formula, output, and supported window types. It is front-loaded and every phrase contributes, avoiding fluff or redundancy beyond the intentional bilingual presentation.

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?

Given the tool's moderate complexity (3 params, no output schema, no annotations), the description covers the main aspects: what it calculates, how (formula), and what it returns (length and off-the-shelf size). It could be more complete by stating the units of the output or explicitly listing all supported window types, but it is still sufficiently complete for a straightforward calculation tool.

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 the baseline is 3. The description adds value beyond the schema by explaining that the length is derived from the sash perimeter (2×(width+height)), reinforcing that 'breite' is the movable part (as schema already notes) and that 'fenstertyp' influences the available coverage. This clarifies how parameters relate to the computation.

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 clearly states it calculates the required window-seal length from sash measurements, provides the perimeter formula (2×(width+height)), and indicates it also returns the off-the-shelf size that fits. This specific verb+resource distinguishes it from siblings like btu_empfehlung or heizleistung_watt, which address other aspects of portable AC selection.

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 gives clear context: it is for portable air conditioners, based on sash measurements, and covers specific window types. It does not explicitly mention when not to use the tool or alternatives, but the context is sufficient since the sibling tools serve clearly different purposes (BTU, power, costs, guides, etc.). A minor omission is that it does not mention the 'kipp' (tilt-only) window type despite its default in the schema.

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