update_media_subscriptions_by_subscription_id

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

Annotations already declare idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds only the HTTP method and the confusing statement that prefs is 'the preference key to retrieve or set' – this is at odds with an update operation and doesn't clarify side effects, scope of changes, or permissions. No meaningful behavioral detail is added beyond the annotations.

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 short and front-loaded, which is good. However, the Args section contains tautological and misleading content, and the useful information (PUT endpoint) is minimal. It could be restructured to explain that prefs accepts an object of preference updates.

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 2-parameter mutation with an output schema, the description is incomplete. It doesn't explain what prefs should contain, whether the update is partial or full replacement, or how success/failure is conveyed beyond the output schema. An agent would struggle to construct a correct request.

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 0%, so the description must explain the parameters, but it fails. 'subscription_id' is just relabeled as 'unique identifier' (tautological), and 'prefs' is described as a 'preference key' while the schema says it's an object of key-value pairs, actively misleading the agent about the expected payload.

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 'Edit a subscription' and includes the PUT endpoint, giving a clear verb and resource. However, it doesn't distinguish this from sibling update_media_subscriptions_by_subscription_id_move or other subscription tools beyond the name, and doesn't specify what fields are editable besides prefs.

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 provides no guidance on when to use this tool versus alternatives such as create_media_subscriptions, delete_media_subscriptions_by_subscription_id, or the _move variant. There is no mention of context, prerequisites, or exclusions, so an agent cannot infer when this is the correct choice.

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