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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description goes further by disclosing what is returned (last-5 and last-10 counts, last-5 values, average) and what the tool is not (no prediction). It does not cover sport-specific quirks or what happens when line is omitted, which is the remaining gap.

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 when-to-use trigger and example, then return shape, then the parameter hint, then the disclaimer — a sensible order with no filler. The inline example query is long but earns its place by disambiguating the stat/line/side combination.

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?

With no output schema, the description carries the burden of describing returns and does so at a useful level (last-5/last-10 counts, values, average). For a 4-parameter read tool it is nearly complete, though it is silent on multi-sport stat-key differences and on behavior when line/side are omitted.

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 each parameter already has a description with examples ('pts', 'points', 'rec_yds', 24.5, over/under). The description only restates that `line` is a number to check, adding no syntax or default behavior beyond the schema, so baseline 3 applies.

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 (how often a player has reached a stat number recently) and lists the supported leagues, giving a concrete example query. It is clearly distinguishable from siblings like search_player (which supplies the player slug) and todays_most_consistent_players (forward-looking consistency rather than per-player historical hit rates).

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?

Opens with an explicit trigger ('Use when the user asks how often...') and an example phrasing, then closes with an exclusion ('Describes past games only. It is not a prediction or a recommendation'), which steers agents away from predictive/consistency requests. The schema's player field also points at search_player for slug resolution.

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