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

With no annotations, the description still carries useful behavioral context: it discloses that this is a paid call ($0.01 via x402), gives the underlying endpoint, and references the output shape ('Same shape as /v1/calendar'). It stops short of describing update cadence/freshness or what 'blended probabilities' aggregates across venues.

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 lead is front-loaded and the bracketed metadata block is compact, but the first two sentences say essentially the same thing ('event resolutions' / 'market resolutions'), diluting an otherwise short description.

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 read-only calendar with no output schema and no annotations, the description covers purpose, output shape, cost, and endpoint reasonably well, but leaves parameter semantics and data freshness unaddressed, so an agent cannot fully call or interpret it without guessing.

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% and the description adds nothing about parameters. The forward window ('days', 1-90) and especially 'category' (a full cross-domain enum that is confusing on an already MLB-filtered tool) are left entirely unexplained in both schema and description.

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+resource: 'Upcoming MLB baseball market resolutions in date order with current blended probabilities.' It clearly differentiates itself from the broader sibling by noting it is 'pre-filtered to MLB baseball markets' versus /v1/calendar, though the first sentence ('MLB baseball event resolutions') largely duplicates the second.

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 via 'the forward calendar of MLB baseball events an agent can position around,' which hints at prospective positioning, but there is no explicit when-to-use, when-not-to-use, or named alternative (e.g. probability_calendar_sports-nba or base probability_calendar). The agent must infer the routing condition.

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