Calculate a 3D print's filament change costs, find ways to reduce them, and include reprint pricing.
What a print's filament changes cost and how to cut them, and the cost with a reprint priced in.
| Name | Required | Description | Default |
|---|---|---|---|
| filaments | No | ||
| file_name | No | Default: "". | |
| file_path | No | Default: "". | |
| printer_id | No | Default: "". | |
| gcode_gz_b64 | No | Default: "". | |
| total_cost_usd | No | Default: 0.0. | |
| estimated_time_seconds | No |
Changes observed during successful MCP inspections.
v1.5.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With zero annotations the description carries the full burden, yet it does not say whether this is a pure read/calculation or mutates state, where pricing data comes from, or how the optional gcode/file inputs affect the result. It gestures at output content (cost breakdown and savings) but not at the behavior an agent needs to trust a call.
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?
It is one short sentence with no filler, but the front-loaded clause is syntactically broken, forcing the reader to reparse it; brevity here costs comprehension rather than buying it.
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?
A seven-parameter cost-analysis tool with no annotations and no output schema needs the description to explain inputs, cost source, and return shape. Instead it supplies one ambiguous clause, leaving the agent unable to know which inputs are needed or how results are framed.
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?
Seven parameters, none required, and the schema descriptions are placeholders ('Default: ""', 'Default: 0.0') rather than meaning. The most important parameter, `filaments`, is an untyped array with no item schema and no description, and the description says nothing about it or about how gcode_gz_b64 vs. estimated_time_seconds is used.
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 sentence implies a cost-analysis tool that reports the cost impact of filament changes plus savings advice and reprint-inclusive cost, but the grammar ('What a print's filament changes cost') muddles the verb. It never disambiguates from the many cost siblings in the catalog (estimate_cost, estimate_material_cost, estimate_print_cost_from_mesh, project_cost_summary, batch_estimate_plate_part_costs).
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?
There is no statement of when to call this versus the other cost estimators, no prerequisites (printer, filament list, gcode vs. file path), and no exclusions. The only hint at usage is the implicit 'how to cut them' recommendation angle.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.