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

Annotations already mark this as a non-read-only, non-idempotent write operation, and the description adds useful context beyond them: each call stores a new feed record with filters only and no personal data, the feed auto-updates, and the result is one-click links for Google Calendar, Apple Calendar, and Outlook. It does not cover auth requirements or lifecycle details, but it meaningfully clarifies the write side effect.

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 three tight sentences with no wasted wording. The core action and return value are front-loaded, followed by the key behavioral note about feed storage and a practical instruction to give links to the user.

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 the fully described 10-parameter schema and annotations, the description completes the picture by explaining what is returned (one-click links for three calendar platforms) and what side effect occurs (a new stored feed record). No output schema is present, but the description sufficiently explains the return and storage behavior for an agent to call it 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 all ten parameters are already documented in the schema. The description refers broadly to filters or a list of event IDs, which aligns with the schema but adds little parameter-level meaning beyond it. A baseline 3 is appropriate when the schema carries the semantic burden.

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 action and resource: creating a personal auto-updating calendar feed from filters or event IDs, and returning one-click subscription links for major calendar providers. This clearly distinguishes it from sibling tools like search_events and get_event, which query or retrieve events rather than create a persistent feed.

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 gives clear context for when to use the tool: when the user wants an auto-updating calendar subscription based on filters or selected events. It also says to give the returned links to the user. It does not explicitly name when not to use it or point to alternatives, so it is strong but not exhaustive.

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