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

Annotations already indicate non-read-only and non-destructive behavior. The description adds that following shows up on the tracker page and enables updates, which is useful context. It does not discuss idempotence or side effects of repeated follows, but the annotation hints cover some of this.

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 concise, front-loaded sentences that clearly state the action and its result. No filler or redundant 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 simple two-parameter tool with a complete input schema and no output schema, the description covers the purpose and effect sufficiently. The sibling list provides additional context for selection, and no critical information is missing.

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%, with each parameter fully described (including an example slug and enum for alert frequency). The description itself adds no additional parameter semantics, so the baseline score of 3 is appropriate.

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 'Follow a public Stock Tracker' with a specific verb and resource, and clearly explains the effect ('shows up on your stock tracker page', 'Get updates'). This differentiates it from sibling tools like add_to_watchlist, which likely adds instruments to a watchlist rather than following a public tracker.

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 context is clear: use this to follow public trackers. It also directs users to discover_community_watchlists for finding slugs. However, it does not explicitly contrast with alternatives like add_to_watchlist or unfollow_watchlist, so it stops short of a full usage guideline.

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