round_sig_figsRound a number to a specified number of significant figures for chemistry and physics calculations. Keeps answers consistent by performing the rounding in tested local code.
Round a number to a given number of significant figures.
| Name | Required | Description | Default |
|---|---|---|---|
| value | Yes | The number to round. | |
| sigFigs | Yes | How many significant figures to keep. |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds no further behavioral context about rounding mode (half-up, banker's, etc.) or handling of edge inputs, which is the one piece of behavior an agent might care about here; with annotations covering the basics, a 3 fits.
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?
A single efficient sentence with no waste, and the key concept (significant figures) is front-loaded. Nothing needs trimming.
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 simple pure-function tool with an output schema, fully documented params, and read-only annotations, the description is nearly sufficient. The only minor gap is not stating the rounding convention, which could matter to callers.
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 100%: 'value' and 'sigFigs' are both documented in the schema, including the exclusiveMinimum constraint. The description repeats the parameter intent without adding syntax or semantic detail beyond the schema, so baseline 3 applies.
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 names a specific verb (Round) and resource (a number to significant figures), making the operation unambiguous. It doesn't explicitly distinguish itself from siblings like convert_units, but those perform clearly different transformations, so misselection risk is low.
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 guidance on when to use this tool versus alternatives, no mention of edge cases (e.g., negative sigFigs, very large/small values), and no exclusions. The agent must infer applicability entirely from the one-line purpose.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.