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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered structurally. The description adds scope context beyond the annotations: it covers both current and past promotions and notes they are grouped under Raising Cane's category headings, which tells the agent what shape of content to expect.

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?

Two tightly written sentences with zero waste. The core identity (what this index contains) is front-loaded, followed by the routing hint to the detail tool.

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-value explanation is not needed, and the description supplies the scope, content grouping, and sibling routing an agent needs. For a zero-parameter index tool this is nearly complete; only an explicit statement of when the index is preferable to another retrieval path is missing.

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?

The tool takes zero parameters, so there is no parameter semantics to describe; the baseline of 4 applies. The description correctly does not invent parameters and instead spends its text on scope and routing.

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 ('promotions index: every current and past sweepstakes, giveaway and other promotion') and explicitly differentiates itself from the sibling raisingcanes_promotion ('Each entry's path chains into raisingcanes_promotion'). An agent can tell this is the listing/index tool versus the detail tool 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?

Provides clear routing context by naming the alternative (raisingcanes_promotion) and explaining the relationship between the two. It stops short of an explicit 'use this when / don't use this when', but the chaining note gives an agent enough to pick the right tool.

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