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

Adds behavior beyond the annotations' readOnly/idempotent profile: it discloses the side-effect boundary ('Does not mark alerts as read'), the result cap (up to 50), the ordering, the 30-day and still-open filters, and the empty-state cause. These are exactly the traits an agent needs to interpret results without re-calling.

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?

Three short sentences, fully front-loaded: what it returns and how it is scoped first, then the side-effect clarification, then the prerequisite. No filler or restatement of the title.

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?

With an output schema present, return values need no prose explanation, and the description still covers filtering, ordering, cap, idempotent non-marking behavior, and the prerequisite. Nothing an agent needs in order to call it correctly is absent.

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?

The tool takes zero parameters, which is the baseline-4 case; there is nothing for the description to disambiguate. The schema confirms an empty properties object, so no parameter semantics are missing.

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?

States a specific verb (List) and resource (alerts from your watchlists) plus precise scope: last 30 days, tenders still open, nearest deadline first, capped at 50. This is clearly separable from get_tender and search_tenders, which query tenders directly rather than the user's watchlist alerts.

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?

Gives a concrete prerequisite that doubles as routing guidance: 'Empty until you create a watchlist with add_to_watchlist', pointing at the sibling needed to make this tool useful. It does not explicitly contrast with get_tender or search_tenders, so it stops short of full when/when-not coverage.

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