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

Annotations already cover read-only/idempotent/non-destructive, and the description adds substantial context beyond them: rounds are planned before play, the tool does not save or publish the event, uneven-rest warnings must be relayed to the user, and the full schedule must be shown round by round. This is rich behavioral disclosure that annotations do not carry.

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 critical precondition is front-loaded in a labeled 'MANDATORY BEFORE CALLING' clause, and sentences are dense with distinct rules. It runs long and repeats the anti-inference rule twice (defaults and the 20-players example), which costs a point but the length is defensible for an 11-parameter tool with routing rules.

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 no output schema, the description usefully specifies the return shape (round-by-round schedule with start time, court, pairs, rests) and how to handle warnings, plus the no-save scope. It is nearly complete, though undocumented parameters like preference and durationMinutes remain a small gap.

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 55%, so several parameters (preference, rounds, durationMinutes, startTime, pointsPerMatch) are undocumented in both places. The description compensates partially by explaining restMinutes and the individuals-vs-fixed-teams distinction tied to names, but leaves the remaining parameters unexplained. Baseline 3 is appropriate.

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 ('Generate an Americano' for padel, rotating doubles, individual entrants) and explicitly distinguishes it from pickleball round-robin and score-led Mexicano pairings. An agent can identify the tool without opening the 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?

Explicit preconditions ('user must have chosen BOTH sport and format'), explicit when-not ('never infer sport or format from... player/court counts or a default'), a named discovery alternative (get_supported_tournament_options), and a concrete routing example for the 20-players/four-courts case. Nothing is left to inference.

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