How to use CabalSpy: the keyless demo, where to get a free API key (1000
requests, no cost), pricing, documentation, and what the data covers. Call
this first if you do not have a key yet, or if another tool returned an auth
error or 'demo_limit_reached'.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "additionalProperties": true,
+ "title": "get_startedDictOutput",
+ "type": "object"
+}Output schema / (root)Previous value: -{
- "additionalProperties": true,
- "title": "get_startedDictOutput",
- "type": "object"
-}New value: +nullDoes 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 genuinely useful behavioral context beyond them: the API works keylessly in demo mode, a free key grants 1000 requests, and this tool is the recovery step after auth/demo-limit failures.
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?
The most important instruction — call this first without a key — is front-loaded, and the enumeration of contents (pricing, docs, coverage) is compact. The list of covered topics is slightly padded but each item tells the agent something it can retrieve.
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?
An output schema exists, so return values need not be described. For a zero-param onboarding tool with annotation coverage, the description supplies everything needed: what it contains, when to call it, and the error states that should route back to it.
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?
The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. No argument syntax is needed or missing.
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 concrete resource — onboarding content: the keyless demo, free API key, pricing, docs and data coverage. Across a sibling set of 20 data-fetching tools, it is unmistakably the meta/onboarding entry point, so an 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?
It states exactly when to call it: 'Call this first if you do not have a key yet, or if another tool returned an auth error or demo_limit_reached.' That is a precise trigger condition plus a failure-recovery path, with no inference required.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.