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

Annotations already declare readOnly/idempotent/openWorld safety, so the bar is lower, and the description adds two genuine behavioral constraints: definitions are not price quotes, and live cannot be combined with date-based discovery. It omits pagination behavior and response shape, and the closing 'catalog metadata' sentence is jargon that resists interpretation.

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 compact sentences with the core capability front-loaded and constraints following. No wasted filler, but the final sentence is dense jargon-heavy shorthand that would benefit from one clarifying clause.

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?

An output schema exists so return values need not be explained. However, with 0 required params, 17% schema coverage, and no enum for sport_id or explanation of the pagination-vs-time-offset distinction, the description leaves an agent guessing about valid inputs and mutual exclusivity of live/date.

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 only 17% across 6 params, so the description must compensate. It implies date, sport_id, and live are mutually constrained (one sport, one date, live vs. date-based), but it says nothing about page/limit/offset semantics — and 'offset' here is a minutes-based date boundary, not pagination, an ambiguity the description does not resolve.

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 ('Discover') and resource (market definitions / available markets) and distinguishes two modes: definitions vs. sport/date-scoped availability. It does not name or contrast itself against any sibling tool such as list_sports or list_events, so it stops short of a 5.

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?

Provides real when-not guidance: do not use definitions as price quotes, and do not combine live with date-based discovery. It also points to catalog metadata for sport/live filters. It never names an alternative tool to use instead, so it falls short of a 5.

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