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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds only the mild note that projections are 'published' and the weekly-mode constraint; it says nothing about what happens with an invalid week, an unpublished season, or a player that exists but lacks a projection.

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, zero filler, with the primary season lookup front-loaded and the weekly fork immediately after. Every clause earns its place.

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?

The output schema covers return values and the annotations cover safety, so the remaining burden is parameter meaning — where a 0% coverage schema leaves model, scoring_format, and season unexplained in both places. Adequate for a lookup tool, but not complete.

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 0% across 7 parameters, so the description carries the full burden — yet it only explains 'player' (ID or slug), 'scope', and 'week'. It is silent on sport, model, season, and scoring_format, four enum-bearing parameters an agent must set correctly.

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 ('look up one player's published season projection') and distinguishes two real modes (season vs. weekly football). It never names the rankings siblings, so an agent gets no explicit contrast against them, but the resource itself is unambiguous.

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?

Gives one concrete conditional: 'Weekly projections require scope=weekly and a week number,' which is useful mode-selection guidance. It stops there — no when-not, no prerequisites, and no routing to get_player_rankings or the ranking tools for roster-wide comparisons.

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