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

Annotations only declare readOnlyHint=false, destructiveHint=false, openWorldHint=false; the description goes well beyond them by spelling out the concrete side effects per format: opponents get walkovers, americano regenerates future rounds, mexicano cancels the unplayed match and re-pairs from standings. This is exactly the 'what actually changes' context the annotations cannot convey. The preview/confirm gate is also disclosed as the mechanism before any mutation lands.

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?

Three tight sentences: action, format-specific consequences, then the confirm workflow. The most decision-relevant information (what changes for opponents) is front-loaded and nothing is padding.

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 preview-gated mutation with an output schema and annotations, the description covers the outcome per format and the confirm flow, which is the critical missing piece in the structured data. It does not mention reversibility (the undo_last_change sibling) or any permission requirement, which are the residual gaps.

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?

With 75% schema coverage the schema already documents confirm, request_id and tournament_key, and the description reinforces confirm via 'Preview first, confirm to apply'. The one undocumented parameter, player_name, is given meaning by the description: it may be the player's pair that is also withdrawn. No syntax or format detail beyond the schema, which is acceptable here.

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 and resource ('Withdraw a player (or their pair)') plus the scope qualifier 'mid-tournament', which is exactly the axis that separates it from the sibling remove_player. It covers the pair case explicitly. It stops short of naming the sibling it must be chosen over, so an agent still has to infer the boundary.

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?

The 'mid-tournament' framing and 'Preview first, confirm to apply' give a clear workflow and context for use. It does not state when NOT to use it or explicitly route to remove_player/replace_player, which is the main remaining gap for an agent choosing among similar siblings.

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