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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds two things annotations cannot: an explicit cost ('Costs 10 credits'), which matters for call budgeting, and a coverage caveat that win probability is only present for limited-overs matches, which prevents misreading sparse output.

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?

The scoping statement is front-loaded, the output summary and cost are each a short clause, and there is no filler. The middle parenthetical list of filters is dense but earns its place as the only enumeration of filter dimensions.

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?

For a 13-parameter read tool with an output schema, this is close to sufficient: return contents, cost, and a win-probability caveat are all present. The remaining gap is the absence of any statement about which filter combinations are valid given zero required parameters, leaving an agent to guess whether calling with no ids returns the whole dataset.

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?

At 69% schema coverage the schema carries most param docs, but the description still adds real meaning: the innings parameter scoped as 'one innings', batter_id/bowler_id explained as pulling balls 'across matches' rather than within one match, and the wickets_only/boundaries_only filters named as such. It does not clarify how the 13 optional parameters combine, or whether any one of match_id/batter_id/bowler_id is effectively required.

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 ('ball-by-ball rows') and enumerates its three scopes: a full match, a single innings, and a batter's or bowler's deliveries across matches. That is concrete enough for an agent to separate it from aggregate siblings such as get_match or get_win_probability without opening a schema.

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 opens with 'Use for ball-by-ball rows', which is real when-to-use guidance, then lists the filter dimensions (competition, season, overs, wickets only, boundaries only). It stops short of naming a sibling as the alternative for aggregate match data, so the routing decision is implied rather than stated.

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