update_subscription

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

With no annotations, the description must carry the behavioral disclosure burden. It only says 'Update subscription parameters,' but does not disclose effects such as whether changes are immediately applied, whether confirmation is required, whether billing is prorated, or what the response contains. For a mutation tool, this is a notable gap.

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 a single concise sentence with no fluff, and the action is front-loaded. It could be slightly more structured by matching the schema parameter names exactly, but it is appropriately compact.

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?

The tool has 8 parameters, no output schema, no annotations, and a modest description. The description omits half the parameters, provides no usage context, and does not mention required fields or operational effects, making it incomplete for an agent to confidently invoke correctly.

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 100%, so the schema already documents all parameters meaningfully. The description repeats a subset of parameter names ('amount, interval, period, description') but adds no additional semantic detail, so the baseline score of 3 applies.

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 ('Update') and resource ('subscription') and lists several updateable parameters. This clearly distinguishes it from sibling tools like create_subscription and cancel_subscription, though it omits several actual parameters from the 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?

No guidance is given about when to use this tool instead of create_subscription, cancel_subscription, or other siblings. There is no context about prerequisites, required fields, or situations where updating is appropriate versus creating a new subscription.

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