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

Annotations already establish the safe, idempotent, closed-world read profile, so the description's job is to add what they can't. It does: it discloses a concrete cost ('Costs 2 credits') and the data provenance (Elo from every final game), both of which materially affect whether an agent should call this repeatedly. It omits any note on ranking scope (all teams vs. a limit).

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?

A single sentence that front-loads the resource and method, then appends the temporal scope and cost. Every clause carries information; nothing is redundant or buried.

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 shape need not be described, and annotations cover safety. The description supplies the pieces structured data can't: provenance, cost, and time basis. Minor gaps remain around ranking extent and whether zero-parameter calls are the common path, but nothing critical for correct invocation 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 coverage is 100%, so both parameters are already documented, including the league enum and the season default. The description's 'as of the end of a season or today' mildly reinforces that season is an end-year with a current-date default, but adds no syntax or format detail 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 names a specific resource (team power ratings) and discloses the method behind it (Elo computed from every final game in the dataset), which implicitly separates it from official-record tools like get_standings. It stops short of explicitly naming a sibling or stating a distinguishing condition, so it lands just under a 5.

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 for our team power ratings ... as of the end of a season or today' gives a usage context and a temporal scope, but offers no when-not guidance and never mentions alternatives such as get_standings or get_team_stats that an agent could easily confuse this with. Usage is implied rather than directed.

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