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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds one useful behavioral fact — pagination happens locally over a bounded vendor response — but says nothing about rate limits, filtering semantics, or what the vendor cap means in practice.

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 tight sentences with the scope statement front-loaded and no filler. The phrase 'bounded vendor response locally' is slightly jargon-heavy but earns its place by disclosing pagination behavior.

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 list tool with no output schema and zero param documentation, the definition is serviceable but thin: an agent still cannot tell the return shape, page-size behavior, or how the archived flag combines with active_only.

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 0%, so the description must carry the load. It gestures at offset/limit and the active/archived flags, covering four of five parameters conceptually, but never explains brand_id as the required key, the limit ceiling of 100, or how active_only and include_archived interact.

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 ('Read') and resource ('promotions for a brand') plus its scope options (active or archived). Siblings operate on brands, entries, and winners, so the resource noun alone distinguishes it, though it never explicitly contrasts with them.

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?

'Optionally active or archived' hints at when the filter flags apply, but there is no explicit when-to-use guidance, no prerequisites, and no mention of alternatives among the sibling list tools.

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