ctr_calculatorCalculate click-through rate from clicks and impressions, or solve for missing clicks or impressions from a known CTR.
Click-through rate (%) from clicks and impressions, or solve for clicks/impressions from a CTR.
| Name | Required | Description | Default |
|---|---|---|---|
| clicks | No | ||
| ctrPct | No | ||
| impressions | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, non-destructive, closed-world behavior, so the safety profile is covered. The description adds that this is a pure computation with an invertible mode, but does not disclose behavior when all three values are supplied, precedence rules, or handling of zero impressions.
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 tight sentence that front-loads the primary computation and appends the inverse mode. Nothing is wasted and no rephrasing of the title.
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 stateless math tool with no output schema and no annotations gap, the description covers the operation and the output unit (%). The remaining ambiguity — how many parameters to pass and which wins when three are given — is minor but real given 0% schema coverage.
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 0% and no parameter is required, so the description must carry the meaning; it does partially, naming clicks, impressions and a CTR percentage and implying that two of the three are supplied. It still omits units for clicks/impressions and does not state the exactly-two-inputs constraint.
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?
Names a specific metric (CTR as a percentage) and the exact inputs it derives it from, plus an inverse mode that solves for clicks or impressions. That is enough for an agent to distinguish it from cpc_calculator/cpm_calculator siblings, though it never explicitly names those alternatives.
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 two modes (compute CTR from clicks+impressions, or back-solve for a missing variable) imply how the tool is used, which is more than nothing. There is no explicit when-to-use versus the sibling calculators and no statement of what is invalid input.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.