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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered. The description adds one genuinely useful trait beyond that: existing redemptions are preserved ("Buyers who used it keep what they got"). It omits whether the coupon record survives, whether the action is reversible, and what error occurs if already discontinued.

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 short sentences, effect stated first, the reassuring side-effect second. No filler, no repetition of the title.

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?

This is an irreversible-sounding destructive mutation with no output schema and only two sentences of prose. It never states what the caller gets back, whether discontinuation can be undone, or what happens to the coupon record itself, which is a real gap for a destructive 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 50%: the context parameter is fully documented in the schema, and id is a required UUID with an obvious format, so the schema carries most of the load. The description adds nothing about which coupon identifier to pass or how to obtain it, leaving the baseline 3.

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?

"Stops a coupon code working" gives a concrete verb-plus-resource and is clearly distinct from create_coupon or update_coupon in intent. It does not explicitly name a sibling or state the boundary (e.g. how it differs from updating a coupon's status), so it stops short of full differentiation.

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?

The description says what happens but never says when to call this instead of update_coupon or remove_plan-style alternatives, nor any precondition (must the coupon be active? can it be re-enabled?). An agent must infer the triggering situation entirely.

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