Set Entity XDATA

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

Annotations alone only say readOnlyHint=false, so the description carries real weight: it discloses that existing XDATA for that app is overwritten, that an empty list deletes it, and that 255-char/16 KB AutoCAD limits are enforced before writing (i.e., validation precedes the write). It stops short of stating what happens to other apps' XDATA on the same entity or how limit violations are reported.

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 sentences, front-loaded with the core action and the removal case, followed by the constraints. Every clause carries information an agent would otherwise have to guess; nothing is padding.

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 mutation tool with minimal annotations and an output schema, the definition covers purpose, destructive replacement semantics, deletion behavior, and input limits. The remaining gap is operational context — permission/app-registration expectations and what a rejection looks like — though 'enforced before writing' partially covers the latter.

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 coverage is 100%, so the baseline is 3, but the description adds meaning not in the schema: the empty-list semantics of 'values' (delete) and the per-entity 16 KB ceiling, which is absent from the parameter docs. handle and app_name gain no extra meaning beyond the schema.

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 states a precise verb and resource: 'Replace the named app's XDATA on one entity,' plus a removal case. It clearly implies the read counterpart (entity_get_xdata) and distinguishes itself from generic setters like entity_set_properties, but it never names a sibling to route the agent explicitly.

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?

Usage is only implied: an agent can infer this is the write-side of per-app XDATA manipulation, and the empty-list case effectively describes the removal workflow. However, there is no statement of prerequisites, when to prefer this over entity_set_properties, or whether existing XDATA should be read first — and 'Replace' implies clobbering that the caller must plan for.

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