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

Annotations declare destructiveHint=true and idempotentHint=true, but the description adds the 30-day pause duration, the one-pause-per-90-day cooldown limit, and the required billing:write scope — none of which are in the structured fields. These are substantive operational constraints an agent needs before invoking; return format is not needed since there is no output schema.

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 front-loaded sentence that delivers duration, cooldown, auth scope, and the confirmation gate with no filler. Every clause earns its place.

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 one-parameter mutation with no output schema, the description covers the key preconditions (confirmation, scope, cooldown) and effect (30-day pause). Nothing an agent needs to call it correctly 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?

Schema coverage is 100% with one boolean 'confirm' parameter, so the schema already carries the meaning. The description restates the confirmation requirement without adding format or edge-case detail beyond what the schema provides — 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?

States a specific verb (pause) and resource (the authenticated user's subscription) plus the scope (30 days). It is clearly distinguishable from siblings like cancel_subscription, resume_subscription, and downgrade_subscription without opening any schema.

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?

Gives an explicit call condition ('Only call after the user explicitly confirms'), which is strong guidance. However, it never routes the agent between this and adjacent choices such as cancel_subscription or downgrade_subscription, so alternative selection is left implicit.

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