list_plansList Caly's plans (Free, Pro, Team) with the monthly USD list price, whether it is per seat, trial days and features. Pass the id to upgrade_plan.
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "list_plans"
}
}| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety is covered. The description adds value beyond that by disclosing the exact field contents (price, per-seat, trial days, features) and the follow-up action, though it says nothing about ordering, pagination, or whether plans are filtered by account region/currency.
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 sentences, front-loaded with the resource and its contents, then the handoff instruction. Every clause carries information; nothing is redundant with the title or annotations.
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 compensates by listing the returned fields, and with zero parameters there is no input burden. Together with annotations covering the safety profile, an agent has everything needed to select and call this correctly.
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 the baseline is 4; there is nothing for the description to disambiguate. The only parameter-like mention ('pass the id to upgrade_plan') refers to a sibling's input, not this tool's schema, which is harmless but not additive.
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 and resource (list plans) and enumerates the concrete fields returned: monthly USD list price, per-seat flag, trial days, and features. It also names the concrete plan set (Free, Pro, Team), so an agent knows exactly what this returns versus sibling list_* tools.
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 sentence 'Pass the id to upgrade_plan' gives an explicit downstream workflow, making clear this is the discovery step that feeds upgrade_plan. It stops short of stating when *not* to call it or naming alternatives (e.g. billing_status for current subscription), so it lacks full exclusion guidance.
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.