marketplace_set_discount

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

Annotations declare a non-read-only, non-idempotent, open-world mutation, and the description adds nothing beyond that: it doesn't say what 'plan' returns versus 'apply', what gets mutated, or whether apply is irreversible. The presence of an undocumented 'confirmation' parameter strongly suggests a guarded write step that the description never explains.

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?

A single sentence with no filler and the resource is front-loaded, so there is no waste. However, brevity here is under-specification rather than conciseness for a six-parameter mutation 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?

Given five required parameters, a low-coverage schema, an undescribed confirmation parameter, and no output schema, this one-liner leaves an agent unable to safely invoke the tool. It should at minimum explain the plan/apply two-step and the confirmation requirement.

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 only 17%, so the description must compensate and it does not. It hints at 'discount' and 'selected locations' (location_ids) and implies the mode, but says nothing about partner_id, application_id, or the unexplained 'confirmation' parameter, which is likely required for the apply path.

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 ('Plan or set') and resource ('Marketplace payment discount') with a scope qualifier ('for selected locations'). No sibling tool deals with discounts, so differentiation is not a problem, but the plan-vs-apply distinction is left implicit.

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?

There is no when-to-use guidance, no mention of prerequisites (partner_id is described in the schema as an ownership check), and no explanation of when to choose 'plan' versus 'apply'. The two-mode workflow is the core usage decision and it is never addressed.

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