List all 30 MLB clubs for a given season, returning IDs, names, leagues, divisions, venues, and active status for quick roster or stats lookups.
List MLB teams. Lists the 30 MLB clubs for a season (four-digit year, default the current year). Each team has its id, name, club name, location, abbreviation, league, division, venue, first year of play and active flag.
| Name | Required | Description | Default |
|---|---|---|---|
| season | No | Four-digit season; defaults to current year |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does well: it discloses the exact count of records returned and enumerates the returned fields (id, name, club name, location, abbreviation, league, division, venue, first year, active flag). It doesn't mention auth or rate-limit behavior, but for a static read-only list that is minor.
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?
Three front-loaded sentences with no filler; the purpose leads and the return-field inventory follows. The field enumeration is lengthy but earns its place because no output schema exists.
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 one-parameter list tool with no output schema, the description supplies the missing return-shape information via the field list, which is what an agent most needs. No output schema means the description compensates adequately; only marginal gaps (e.g., ordering) remain.
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 100% and the schema already documents `season` as a four-digit year defaulting to the current year. The description repeats that same information rather than adding format constraints or edge-case behavior (e.g., invalid years), so the baseline 3 is appropriate.
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+resource ('List MLB teams') and quantifies scope ('the 30 MLB clubs'), so an agent immediately knows this is the full team catalog rather than stats, rosters, or standings. It does not explicitly name or contrast with the many sibling mlb_* tools (mlb_team_stats, mlb_team_roster, mlb_standings), which keeps it short of a 5.
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?
Usage is only implied: the agent can infer this is for enumerating clubs by season, but there is no explicit when-to-use statement, no mention of alternatives (e.g., use mlb_team_stats for performance data), and no prerequisites. Minimum viable context, no exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.