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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds useful specifics beyond that: it discloses which state changes occur (future outreach disabled, unsent messages cancelled), which is exactly the kind of side-effect detail the hints cannot convey.

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?

The functional sentence is short, front-loaded, and free of filler. The only waste is restating the tool title as a standalone heading above the actual description, which adds no information.

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 an output schema present, return values need no explanation, and the annotations carry the safety profile. The description supplies the remaining essential context: what the customer state change actually is. Nothing critical for correct invocation 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?

There is a single required parameter whose schema description coverage is 100% ('Unique numeric identifier for the customer'), so the schema fully documents it. The description adds no format, lookup, or resolution guidance beyond the word 'customer', making the baseline 3 appropriate.

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?

The description states a specific verb and resource ('Unsubscribe a customer') and goes further by naming the effect: halting future outreach and cancelling queued messages. It is clear what the tool does, but it does not distinguish itself from close siblings like cancelCustomerUnsentMessages or resubscribeCustomer, which overlap with its described behavior.

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 rather than stated: the described effect (stop future outreach, cancel unsent messages) tells an agent what situation calls for it. However, no alternatives or exclusions are named despite the presence of directly relevant siblings such as cancelCustomerUnsentMessages (partial overlap) and resubscribeCustomer (the inverse operation), and no preconditions are given.

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