list_materials

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

With no annotations, the description carries the full burden. It discloses the read-only listing behavior and the filtering capabilities, which is helpful. It does not mention pagination, authentication, or potential rate limits, but for a simple list operation this is acceptable. The behavior is transparent enough for an agent to understand it is a non-destructive read.

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 and well-structured: one clear purpose line followed by a succinct args list. Each argument is explained in a single line with no redundant content, making it easy to parse quickly.

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?

The description covers the core purpose and all three parameters, and the presence of an output schema handles return value details. It does not discuss edge cases like empty results or authentication, but for a straightforward list tool with optional filters, it is sufficiently complete.

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%, but the description fully documents each parameter: search by material or brand name, material_type with allowed values 'generic' or 'blueprint', and favorites as a boolean filter. This adds crucial meaning beyond the bare schema property definitions and clarifies the expected values.

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 starts with a specific verb 'List' and clearly defines the resource as 'filament material blueprints and generic material types'. This distinguishes it from sibling tools like list_spools or list_brands, making the tool's purpose immediately obvious.

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 implies usage when you need to view material definitions, and the parameter explanations (search, material_type, favorites) provide context on how to filter. However, it does not explicitly contrast with related tools like list_spools or create_material, so guidance on when to use this versus alternatives is only implied, not stated.

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