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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real context beyond that: result ordering (next lock first), timezone for lock values (US Eastern), and that page is the slate's free web page. It doesn't mention pagination or empty-result behavior, but for a small read-only listing this is solid.

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?

Everything is packed into roughly two sentences, with the identification and ordering front-loaded and the chaining hint last. The field enumeration earns its space because there is no output schema.

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 fills the gap by listing returned fields, and it covers ordering, timezone, and the downstream chaining step. Only minor items such as empty-result or pagination behavior are absent, which is acceptable for a simple two-parameter list tool.

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% with both parameters as documented enums, so the schema already carries full parameter meaning. The description only restates 'filter by site or sport' without adding format or default-behavior detail, so the baseline 3 applies.

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 ('Lists the open DraftKings and FanDuel slates'), the ordering rule ('the next lock first'), and enumerates exactly which fields come back. It explicitly names the sibling top_players and the handoff slateId, so an agent can distinguish the two tools without opening either 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?

Gives concrete usage context: 'Filter by site or sport' explains the two optional parameters, and 'Use a slateId with top_players' tells the agent when to chain to the sibling. It stops short of explicit when-not-to-use guidance, which is the only gap.

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