Set the default league (and your team in it) used when later commands omit keys. Use for 'fantasy choose team'.
AI agents use fantasy_select_team to create or update resources in Yahoo Fantasy Baseball — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Yahoo Fantasy Baseball environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
teamKey | string | — | Your team key, e.g. 431.l.12345.t.2 |
leagueKey | string | Yes | League key, e.g. 431.l.12345 |
Parameters from the server's own tool schema.
The tool performs a configuration/preference update by storing a default team selection. This is a reversible write operation (the user can select a different team later). It has no destructive, financial, or code-execution implications. The blast radius is minimal since it only affects which team context is used for future commands, and can be easily changed.
From the tool's definition Tool description states 'Set the default league (and your team in it)' — this modifies stored user preferences/state for subsequent operations.
Attacks that exploit this kind of access
Set the default league (and your team in it) used when later commands omit keys. Use for 'fantasy choose team'. It is categorised as a Write tool in the Yahoo Fantasy Baseball MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
fantasy_select_team accepts 2 parameters: teamKey, leagueKey. Required: leagueKey. The full parameter table on this page comes from the server's own tool schema.
Register the Yahoo Fantasy Baseball MCP server in PolicyLayer and add a rule for fantasy_select_team: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Yahoo Fantasy Baseball. Nothing to install.
fantasy_select_team is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the fantasy_select_team rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for fantasy_select_team. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
fantasy_select_team is provided by the Yahoo Fantasy Baseball MCP server (yahoo-fantasy-baseball-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
fantasy_select_team is one line of Yahoo Fantasy Baseball's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
Teams ship this data inside their own products. See what a licence covers →