update_ical_subscription

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

Annotations indicate idempotent and non-destructive. Description adds a useful behavioral note: 'Changing the URL forces a full re-sync on the next poll.' This goes beyond the annotations and helps the agent understand side effects. No contradictions.

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?

Two sentences, no wasted words. First sentence states purpose and scope, second sentence adds a critical behavioral detail. Front-loaded and efficient.

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?

Given no output schema and 3 straightforward parameters, the description covers the key aspects: what the tool does, which fields can be updated, and a side effect. It does not mention that subscription_id is required (but schema handles that) or that at least one of label/url should be provided. Overall adequate for the tool's complexity.

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%, so schema already describes parameters. The description adds context about the url parameter's effect (forces re-sync), which provides additional meaning beyond the schema's format/pattern constraints.

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?

Description clearly states the verb 'Update' and the resource 'external iCal feed subscription', and specifies the changable attributes (label, feed URL). It is distinct from sibling tools like subscribe_ical, delete_ical_subscription, and sync_ical_subscription.

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 implies when to use (when you need to change label or URL) but does not explicitly state when not to use or mention alternatives such as deleting and re-subscribing. No exclusion criteria are provided.

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