get_material_layer_parameter

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds the non-obvious behavior that a 'found' flag is returned, which discloses how missing parameters are handled. It stops short of any further behavioral nuance (e.g. what happens on an out-of-range layer_index).

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?

Front-loads the core action and scoping, and every clause (read-back oracle, layer association, return shape) carries information. The middle sentence is dense with an em-dash aside, but it earns its place by differentiating the sibling. Slightly more compact phrasing would reach 5.

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 read tool with four fully documented required parameters, a covered safety profile, and no structured output schema, the description supplies the missing return shape (including the value union and found flag). An agent has everything needed to call it and interpret the result.

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 100%, so the schema already documents all four parameters including the zero-based layer_index. The description implies the layer_index scoping and the value type union but adds no syntax or format detail beyond what the schema provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (Read), resource (one parameter's value), and scope (a specific layer of a layered material instance, keyed by zero-based layer_index). It explicitly distinguishes itself from the sibling get_material_all_parameters, so an agent can select it without opening either schema.

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?

Names the alternative tool (get_material_all_parameters) and gives the exact condition that selects each: use this one when you already know the slot because the broader tool is 'noisier'. It also frames itself as the read-back counterpart to set_material_layer_parameter, giving clear when-to-use context.

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