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

Annotations already indicate readOnlyHint=false, destructiveHint=false, idempotentHint=false, so the agent knows this is a non-read, non-destructive, non-idempotent operation. The description adds that it marks milestones as celebrated and returns the count, which is useful. It doesn't disclose side effects like whether dismissed milestones can be re-dismissed or if this affects gamification state beyond visibility, but the annotations cover the basic safety profile.

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-loaded: a one-sentence purpose, then Args and Returns sections. Every sentence earns its place, and the format is easy to scan.

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 one-parameter tool with no output schema, the description covers the main action and return value. It lacks details about error behavior, whether the operation is idempotent (annotations say it isn't), and how it relates to the gamification system's celebration lifecycle. Given the simplicity, it's adequate but not rich.

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 0%, so the description must compensate. It does explain that milestone_ids is a list of milestone IDs to dismiss, which adds meaning beyond the raw schema. However, it doesn't specify constraints like whether IDs must be valid existing milestones, whether duplicates are allowed, or what happens if an ID is invalid. The description provides the core semantic but not edge-case guidance.

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 ('Mark') and resource ('financial milestones as celebrated'), and clarifies the user-facing meaning ('user has seen them'). It is distinguishable from siblings like dismiss_budget_recommendation and dismiss_payment_warning by the resource type, though it doesn't explicitly name those alternatives.

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 usage: call this when the user has seen a financial milestone and it should no longer be shown as a celebration. It does not explicitly state when not to use it or mention alternatives like get_celebrations or list_milestones, but the context is reasonably clear.

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