Add surface from library

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

Annotations declare readOnlyHint=false and destructiveHint=false but say nothing about side effects. The description usefully discloses that this pulls in dependent materials ('pulling in any materials it needs'), which is real behavioral information beyond the structured fields. It stops short of saying what happens if the requested ID already exists or whether the copied materials are shared or duplicated.

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 core action is front-loaded in a single efficient sentence with no filler. The appended '[bulc-mcp rules]' fragment is terse to the point of being cryptic, slightly weakening the structure, but nothing is wasted.

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 write operation with no output schema, the description covers the essential outcome (a &SURF is created plus its materials), which is adequate. It leaves open collision handling on the target ID and the exact source of valid library IDs beyond a GUI pointer, so it is complete enough to attempt the call but not to predict failures.

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% with only two parameters ('library_id' and optional 'id'), so the schema already documents both, including the default behavior of 'id'. The description adds no syntax, format, or sourcing detail beyond what the schema states, so the baseline 3 applies.

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 uses a concrete verb+resource: 'Copy a surface preset from the built-in library into the model as a &SURF,' which is materially distinct from add_surface (manual creation) and add_material_from_library (different resource). It does not explicitly name or route against those siblings, so an agent must infer the distinction from the phrase 'from library.'

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?

There is no explicit statement of when to choose this over add_surface or assign_surface. The trailing fragment '[bulc-mcp rules] SURF-001 — bulc_knowledge_search "<id>"' implies a rule-compliance step but is opaque enough that an agent cannot tell what precondition it must satisfy before calling.

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