get_promotion

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

The readOnlyHint annotation already establishes this is a safe read, so the description only needs to add context. It adds value by enumerating what the record contains, but says nothing about behavior on an unknown/invalid ID, auth requirements, or payload size.

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?

One compact, front-loaded sentence with no preamble. The trailing 'etc.' slightly weakens the otherwise precise field enumeration, but nothing is wasted.

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 usefully enumerates the returned fields so an agent knows what to expect. For a simple one-parameter read tool this is largely sufficient; only error/auth behavior is unaddressed.

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 100% for the single 'id' parameter, so the schema already carries the semantics; the description's 'by ID' merely restates it. Baseline 3 is appropriate when the schema does the heavy lifting.

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 ('Get full promotion details by ID') and enumerates the payload (name, type, schedule, discount rules, coupon settings, items, bonus products). It clearly distinguishes a single-record fetch from the list/search siblings, though it never names them explicitly.

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 by 'by ID' – call it when you already have a promotion ID. There is no explicit when-to-use or when-not-to-use guidance, and the closely related siblings (get_active_promotions, search_promotions, list_promotions) are not referenced for disambiguation.

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