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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely non-obvious behavior: all figures derive from the ball-by-ball record beginning December 2001, so earlier careers are truncated, and each call costs 5 credits — a real cost constraint worth flagging.

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?

It is a single front-loaded sentence leading with the use case, then scope, provenance, and cost in that order. The long parenthetical enumerations of batting and bowling fields are dense but do tell the agent exactly what coverage to expect.

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 an output schema present, return values need not be explained, and the description covers provenance, format dimension and credit cost. The one meaningful omission is how this differs from get_player_stats, which matters given the near-identical sibling.

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 description coverage is 100% and player_id is documented as coming from search_players, so the schema carries the parameter burden. The description's 'by format' hints at the league parameter's effect but adds no syntax or default detail beyond it, which is the baseline-3 case.

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 resource and scope: a player's career, with enumerated batting and bowling metrics by format. It does not distinguish itself from the close siblings get_player_stats or get_player_matches, so an agent comparing them still has to guess which returns what.

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 a player's career' implies the usage context, and the required player_id sourcing is in the schema, but there are no explicit when-not conditions or named alternatives despite get_player_stats and get_player_matches sitting right beside it.

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