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

Annotations already declare a safe, idempotent, closed-world read. The description adds genuine behavioral detail beyond them: the implicit default round (latest finished) and the strokes-gained fallback logic disclosed via 'sg.source' when Garmin GPS shots are absent. It does not say what happens if no finished round exists, nor whether 'PRO' implies a subscription/tier gate.

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?

Front-loaded with the purpose, then the two conditional clauses at the end; no filler sentences. It is a single dense run-on enumeration, but since there is no output schema the metric list is doing useful work rather than 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?

With no output schema, the description correctly compensates by listing the returned metrics, and it covers both parameters' defaults and the source enum. Gaps are minor: no error/empty-state behavior (no finished rounds) and no clarification of what 'PRO' means for callers.

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 the baseline is 3, but the description adds a modest amount: it ties the absence of round_id to a concrete semantic outcome (last finished round) and frames 'rfeg' as an official federation round source. Most of this restates the schema descriptions, so the added value is real but small.

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 opens with a specific verb+resource ('Resumen PRO de una vuelta del jugador') and then enumerates exactly which metrics are produced (resultado contra par por tipo de hoyo, putts, calles, GIR, scrambling, penalidades, strokes gained, comparación con la media). That enumeration clearly separates it from siblings like get_round_card or get_strokes_gained_by_area, though no sibling is named explicitly.

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?

Usage is implied rather than stated: it explains the default when round_id is omitted ('Sin round_id: su última vuelta terminada') and when to pick source='rfeg'. There is no explicit when-to-use-this-vs-alternative routing (e.g. versus get_round_card, get_scorecard_stats, or get_player_insights), so the agent must infer selection from the metric list.

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