check_api_keyReports the plan and remaining daily and monthly quota for a Zactonz API key by product, so you can monitor usage limits. Costs nothing.
Reports the plan of a configured Zactonz API key and the quota it has left today and this month. Costs nothing.
| Name | Required | Description | Default |
|---|---|---|---|
| product | Yes | The product whose key to check. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint and openWorldHint, so safety is partly covered, but the description adds genuinely new behavioral facts: it reports both daily and monthly quota remaining, and 'Costs nothing' tells the agent the call consumes no quota. It stops short of covering invalid/missing-key behavior or return shape.
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?
Two tight sentences with the returned information front-loaded and the zero-cost caveat last. No filler or restatement 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?
With no output schema, the description does the work of naming the returned fields (plan, daily quota, monthly quota) and the cost profile. It omits edge-case behavior such as unconfigured or invalid keys, which is a minor gap for a single-parameter read tool.
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% with a single enum-constrained 'product' parameter that is fully documented in the schema. The description adds nothing beyond the schema for this parameter, so the 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?
States a specific verb ('Reports') and resource (plan of a configured Zactonz API key plus its quota for today and the month). No sibling tool inspects API keys, so the agent can distinguish it without opening the schema.
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 description implies a pre-flight use case via 'Costs nothing' (safe to call freely), but never states when to call it versus alternatives or what happens when no key is configured. Usage is implied rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.