list_spools

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

With no annotations, the description carries the full burden. It provides useful behavioral details like the meaning of is_archived (show only archived vs exclude archived) and that color does fuzzy matching. However, it does not explicitly state that this is a read-only operation, nor does it disclose default behavior when is_archived is null (e.g., whether archived spools are shown by default). Side effects are not mentioned, though a list operation likely has none.

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 concise and front-loaded: one sentence states the purpose, followed by a bullet-list of parameters, each explained in a single line. No filler words or redundant schema repetition. Every sentence adds value.

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?

Given a tool with 4 optional parameters, no annotations, and an output schema present, the description covers the core behavior and all parameters meaningfully. It lacks only minor details like the default behavior when is_archived is not provided, and whether filters are AND-combined. These are small gaps, so the description is mostly complete for practical use.

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?

The input schema provides only types and defaults (string/integer/boolean, null), with 0% schema description coverage. The description adds substantial meaning: enumerates valid status values, clarifies printer filter is by ID, specifies color is a fuzzy match, and explains the two branches of is_archived. This fully compensates for the lack of schema descriptions.

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 'List filament spools with optional filtering' – a specific verb, resource, and scope that clearly distinguishes it from sibling tools like list_materials or get_material_spools. The purpose is unambiguous and immediately concrete.

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?

It clearly states the tool is for listing filament spools with optional filters, giving a clear context for when to use it. It does not explicitly mention alternatives or exclusions (e.g., for spools tied to a specific material, use get_material_spools), but the purpose itself is distinct enough that the lack of explicit alternatives is not a major gap.

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