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

Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint false, openWorldHint), so the bar is lower, yet the description still adds real context: live data, prices only "when published", a provider booking page in the response, and an explicit no-booking/no-payment boundary. It does not cover freshness/caching, empty-result behaviour, or how the open-world provider scope affects reach.

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, front-loaded with the triggering condition, then return values, then the behavioural boundary. Every sentence earns its place and there is no filler.

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?

The output schema means return values need not be detailed, and the description still summarises them usefully. But for a 10-parameter tool with zero schema descriptions and two enums, the absence of any parameter guidance leaves an agent guessing at how to set search_days, radius_km, player_level or availability correctly.

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 0% across 10 parameters, so the description carries the full burden, and it explains none of them. The activity examples partially mirror the category enum (social, coaching, training, intro, junior, competition) but omit league, tournament and other, and nothing is said about location, start_date, search_days, radius_km, availability, player_level (1-7 scale), earliest_time or limit.

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 (search) and resource (scheduled PadelStars activities), then enumerates the categories of activity covered (coaching, training, intro, socials, junior, competitions). That enumeration implicitly separates it from search_public_games and search_courts, but no sibling is ever named explicitly, so an agent must 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?

"Use this when a player wants scheduled PadelStars activities" gives a clean triggering condition, and the category list narrows the case further. It also rules out booking behaviour, which points at get_booking_handoff by implication, but no alternative tool is named and no when-not-to-use case is spelled out.

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