material.assign

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

Annotations already declare mutating, destructive, and idempotent behavior. The description adds meaningful context beyond those flags: shared data has an explicit user-count and permission requirement. It does not contradict the annotations.

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 description is short and front-loaded, with no filler wording. However, the second sentence is compact to the point of being cryptic; it could preserve its length while being clearer about which parameters the permission requirement refers to.

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?

This is a 14-parameter mutation tool with 8 required parameters, including multiple identity and expected-state fields, yet the description only covers slot operations and the shared-data permission condition. An agent would not know how to correctly populate expected_object_identity, expected_data_identity, expected_scene_generation, idempotency_key, and related fields.

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 0%, so the description must carry the parameter burden. It only hints at mode ('append, replace, or clear'), slot_index ('one exact material slot'), and expected_data_users/allow_shared_data ('exact user count and explicit permission'). The many required identity, transaction, and idempotency parameters are left unexplained.

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 names a specific set of operations ('Append, replace, or clear') on a specific resource ('one exact material slot on inspected object data'). This clearly distinguishes material.assign from nearby siblings like material.create or material.set_input.

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 a concrete precondition for shared data ('requires its exact user count and explicit permission'), which is useful usage guidance. However, it does not name alternatives or state when to use this tool over material.set_input, object.set, or material.texture.bind.

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