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

Annotations already declare the safe read profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description still adds meaningful behavior beyond them: the data is cumulative and aggregated across all sessions for the team, which is the key distinction from per-session tools.

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: the first front-loads what is retrieved and its scope, the second gives use cases. Nothing is repeated from the title or schema.

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 annotations cover the safety profile. Scope, content and usage are all covered; only the pagination/limit nuance is left implicit, which the schema largely handles.

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?

There is only one parameter (limit) and schema description coverage is 100%, so the schema already documents range and default. The description says 'every player's total score' but does not clarify that the result set is capped by limit, adding no meaning beyond the schema; 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?

The description gives a specific verb and resource ('Get the all-time Fun Friday leaderboard'), names the scope (user's team, all sessions) and enumerates the returned fields (total score, games played, rank). An agent can distinguish it from the sibling session/game/team tools on the resource alone.

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 provides concrete usage triggers ('who is top of the leaderboard?', 'write up a standings summary'), which is clear positive guidance. It stops short of naming alternatives or stating when not to use it (e.g., a single-session view via funfriday_get_session).

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