player_history

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden and does so reasonably: it warns 'NEEDS A TOKEN, unlike most reads here,' and discloses that history spans seasons via the previous_league_id chain. It doesn't state whether the call mutates anything (it clearly doesn't) or any rate limits, but the auth and scope disclosures are valuable.

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?

Front-loaded with the core purpose and the token requirement, followed by Args. The prose paragraphs on free-agent reasoning and cross-season history are somewhat expansive but each adds useful decision context, with little pure filler.

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?

Given no annotations, an output schema present, and 0% schema coverage, the description covers purpose, auth, cross-season scope, and all three parameters. It is close to complete for an agent to invoke correctly, with only minor gaps like no mention of ordering or result shape.

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 0%, so the description must compensate and does: it explains player_name accepts full or partial names, limit sets transaction count (default 25), and league_id_ overrides the configured league. This adds meaning well beyond the bare schema types.

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 states a specific verb and resource: 'Every time this league has added, dropped or traded one player.' The 'one player' scoping distinguishes it from the broader 'transactions' sibling, though no sibling is named explicitly, so an agent must infer the boundary.

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 gives concrete usage context: 'Useful for deciding whether a free agent is genuinely available or merely between owners,' framed by the waiver-wire example. That is clear when-to-use guidance, but it names no explicit alternative tool or exclusion condition.

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