Does 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 new operational context — the list is dynamic, community-maintained, not paginated, and legacy entries may be incomplete. That last point is important for an agent that might otherwise treat missing leagues as authoritative. It stops short of 5 because it doesn't say how large the unpaginated payload can get.

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 sentences, each doing distinct work: what is returned, how to use it for discovery, and what caveats to expect. The primary behavior is front-loaded and nothing is redundant with the schema 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?

An output schema exists, so return values need no explanation, and the description covers the remaining gaps an agent would care about: the unpaginated full-list behavior, data volatility, and the discovery-first workflow. Nothing needed to call this correctly is missing.

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% and the single parameter is fully documented in the schema, so the baseline of 3 applies. The description reinforces the 'starting year' semantics and the omit-to-return-all behavior, but adds no syntax or format detail beyond the schema.

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 uses a specific verb and resource ('Return every OpenLigaDB league-season row'), states both modes (all rows vs. one starting year), and makes clear this is a discovery/reference endpoint rather than a match or table query. An agent can distinguish it from openligadb_sports, openligadb_groups, and openligadb_teams 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?

'Use this first to discover exact league_shortcut, league_id, leagueSeason, and sport values for all match, group, team, table, and result endpoints' is an explicit use-this-before-that directive naming the downstream endpoints that depend on its output. It does not state a when-not-to-use condition or name a competing sibling, so it falls just short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.