mat_create_standard

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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the safety profile is known. The description adds the 'looks dated under PBR' caveat and mentions optional assignment, but it does not disclose the concrete destructive effect, such as whether assigning replaces existing materials on target objects.

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 compact, front-loaded with the core action, and includes a clearly marked usage caveat with the preferred alternative. The bilingual repetition is purposeful for the audience, and every sentence contributes useful information.

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 three-parameter tool with no required parameters and no output schema, the description covers creation, optional diffuse colour, optional assignment, and the sibling preference. The main gap is the absence of explicit side-effect details around assignment, but the destructiveHint annotation partially mitigates that.

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 input schema already documents all three parameters. The description mostly repeats that diffuse is optional and that objects may be assigned, without adding new detail about formats, defaults, or edge cases 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 ('Create'), the exact resource ('StandardMaterial'), and the optional behaviors (diffuse colour, assignment). It also names the preferred alternative, mat_create_physical, allowing an agent to distinguish this from the family of mat_create_* tools.

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?

Explicitly says this material looks dated under PBR/physical lighting and directs new work to mat_create_physical. This is a clear when-to-use vs when-not-to-use instruction, naming the alternative and the condition that selects it.

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