Modify shells

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

Annotations declare readOnlyHint=false, destructiveHint=true, idempotentHint=true. The description adds meaningful context beyond that: the type restriction (only Extruded/Revolved/Ruled cannot change class; a subset cannot change class), patch semantics ("only the given fields change"), per-item continuation on error, return shape ordered by input, and that mutations are in one undo step. These are valuable behavioral details the annotations do not capture.

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?

Compact, front-loaded with the verb and type constraint, and then patch and return semantics. Every sentence carries content, though the long field enumeration could be tighter.

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 no output schema, the description covers the important behavioral contracts: partial update, per-item error isolation, ordered return, and undo grouping. It lacks explicit permission/auth notes but is strong given the schema's richness.

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 schema already documents all parameters. The description lists some fields (profile, placement, angles, thickness, etc.) and cross-references create_shells for full field semantics, which is helpful but does not add syntax or format details 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?

States a specific verb+resource ("Changes existing shells") and immediately names the sibling create_shells as the source of the field semantics. It is easy to differentiate from sibling modify_elements or create_shells.

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 notes fields follow create_shells, but does not state when to use modify_elements vs modify_shells, or when not to (e.g., can only modify existing shells, not convert types). Context is implied rather than explicit.

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