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

Annotations already indicate mutation (readOnlyHint=false) and idempotence (idempotentHint=true). The description adds important behavior beyond that: 'The result is saved even with issues' and 'free on beispiel-wohnzimmer (not saved)' disclose persistence semantics and a key edge case that annotations do not capture. It also clarifies that the returned artifact is an image with issues, which is useful context.

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?

Three tightly written sentences front-load the core action and return value, then pack usage constraints, persistence, and authentication caveats into minimal words. Every clause adds operational value; there is no filler or repetition.

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 complex mutation tool with 9 parameters and no output schema, the description covers the critical aspects: main actions, parameter grouping, return type (image with issues), save behavior, key requirement, and the non-save exception for beispiel-wohnzimmer. It does not mention index/variant handling in prose, but those are fully covered in the schema, so the description is sufficiently complete for correct invocation.

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?

The input schema already provides 100% coverage with detailed descriptions for all 9 parameters, so the baseline is 3. The description's parameter guidance ('Send x and y together (piece center, meters), rot, or remove true') reinforces the schema but does not add new semantic information beyond what is already in the parameter descriptions.

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 opens with 'Moves, rotates or removes one piece in the saved layout', which is a specific verb+resource combination that clearly differentiates this tool from siblings like place_furniture (adding new pieces) and check_plan (checking without moving). It also states the return value ('returns the re-checked plan as an image with issues'), making the tool's function unambiguous.

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 operational instructions ('Send x and y together ... rot, or remove true') and implies iterative use ('read them and move again if needed'), but it never explicitly says when to use this tool versus alternatives like place_furniture or set_door. No exclusions or alternative routing is provided.

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