find_closest_filaments

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

With no annotations, the description carries the full burden. It usefully discloses the result shape cap (up to three per colour) and cross-manufacturer diversity, but says nothing about sourcing/privacy implications, whether it queries live vendor data versus internal catalogues, whether inventory is considered, or whether the call has any side effects.

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?

Three short sentences, with the core purpose front-loaded ahead of the invocation gate and the result-shape constraint. No filler, though the question phrasing is slightly oblique for a machine-consumed instruction.

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?

No output schema exists, so the description's 'up to three per color, from different makers' is the only signal about return values and it partially compensates. Against four parameters with thin schema descriptions and no annotations, gaps remain around the optional filters and what each returned filament record contains.

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 nominally 75%, but the three documented parameters only carry 'Default: ""' placeholders, and `colours` (the required array) has no description at all. The description's 'for this color' implies the colour input but never explains the brand, finish, or material filters or whether they narrow or expand results.

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 opening question plus the constraint 'Up to three per color, from different makers' makes clear this retrieves purchasable filament matches for a given colour, with diversity across manufacturers. It does not name any sibling (e.g. find_material_substitute, get_best_material_substitute, fleet_colour_match) to differentiate itself, so an agent must infer the boundary.

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?

'Call ONLY when the person asks' is a real gating condition that prevents unsolicited invocation, which is more than most definitions offer. However, it gives no guidance on when a different tool (material substitute lookup, generic material recommendation) would be the better choice, so the alternative routing is left to inference.

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