Shape set item fds props

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

Annotations already establish mutation/non-destructive/idempotent, so the bar is lower. The description adds genuinely non-obvious behavior: the change is edited via the Library FDS Properties panel and only takes effect when the item is placed, and that it installs a 'fire' preset override. It does not describe handling of unset fields, which is the one remaining gap.

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 operation and scope, no filler. The UI-button aside is mildly parenthetical but earns its place by explaining where the value surfaces.

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 15-parameter mutation tool with no output schema, the description covers what it targets and when it takes effect but omits whether the set is a full replace or a partial merge, and how the required item_id must be sourced (only implied by the schema). Adequate but with clear gaps.

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 60%, so the schema documents most parameters with units (kW/m², °C, kJ/kg, etc.). The description only supplies group-level framing ('fire/material properties', 'fire preset override') and adds no per-parameter meaning for the undocumented tail, leaving it between the high- and low-coverage baselines.

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?

Specific verb (set) plus resource (FDS fire/material properties) plus target (a registered item), and it frames the scope as the item library. An agent can separate it from the getter sibling shape_get_item_fds_props, though it does not name that sibling 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?

The description implies when this is relevant (item-library FDS properties, applied when an item is placed), which gives usable context. It never states when to prefer this over shape_set_params or set_fds_properties, nor any exclusions, so no explicit routing guidance.

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