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

Annotations already establish readOnly, idempotent, and non-destructive behavioreding. The description adds meaningful state-based context beyond those annotations by clarifying that only uncelebrated, unseen achievements are returned. It does not contradict 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 compact and front-loads the core action before the return clarification. Every sentence earns its place, with no filler or redundant restatement of the tool name.

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 zero-parameter read-only tool, the description is largely complete: it states the input is none and the output is a list of unseen milestone achievements. It could be slightly stronger by noting whether fetching marks them as seen or whether dismissing must be handled separately, given the sibling tool dismiss_celebrations exists.

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?

There are zero parameters, so the schema has no parameter details to provide. The baseline of 4 applies here because the description accurately frames the tool's input-free invocation and reinforces that it returns a list without requiring arguments.

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 verb ('Get') and a specific resource ('uncelebrated financial milestones'), while the return clause clarifies these are milestone achievements the user hasn't seen yet. The phrase 'for celebration animations' adds context and helps distinguish this from plain milestone listing tools like list_milestones.

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 call this tool: to obtain pending, uncelebrated milestones for celebration animations. It does not explicitly name alternatives or when-not-to-use conditions, but the pending/unseen scope is enough to separate it from related sibling tools.

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