ls_update_subscription

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

Annotations declare readOnlyHint=false, destructiveHint=false, but the description adds crucial nuance: certain parameters (pause, variantId) are destructive and rate-limited/audited, while others are not. This goes beyond the annotations and helps the agent understand behavioral impact and side effects.

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 description is two sentences, front-loaded with the verb and resource, then packing significant detail without fluff. Every sentence adds critical selection and usage 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?

For a complex 8-parameter mutation tool with no output schema, the description covers the main capabilities, destructive implications, and boundary with sibling tools. It provides sufficient context for an agent to select and invoke the tool correctly, with parameter details delegated to the schema.

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 detailed descriptions for each parameter. The description enhances this by grouping parameters into impactful vs. neutral categories, explaining the consequence of pause/variantId, and clarifying the cancellation exclusion. This adds strategic meaning beyond raw schema definitions.

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 clearly states the tool updates a subscription and enumerates specific actions (variant change, pause/unpause, billing anchor, invoice details). It differentiates from the sibling ls_cancel_subscription by explicitly directing cancellations to that tool.

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?

Provides explicit guidance on when to use this tool versus alternatives: distinguishes customer-impacting destructive operations (pause, plan switch) from non-destructive ones, and explicitly states to use ls_cancel_subscription for cancellation. This gives clear decision criteria for an agent.

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