Per-app statistics

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

No annotations exist, so the description carries the full burden; it does disclose the exact return metrics, which is genuinely useful given there is no output schema. It says nothing about behavior for an unknown bundle id (empty stats vs error), whether it is purely read-only, or performance over long time windows.

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 sentences, zero filler: the metric list comes first and the illustrative use case second. Everything is front-loaded and each phrase maps to a dimension the agent cares about (content and usage).

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 read tool with no output schema, enumerating the returned metrics plus a usage example is close to sufficient. The remaining gap is edge-case behavior (missing/unknown bundle) which the description does not address.

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 coverage is 100% and both parameters (bundle, since) are fully documented with examples and the default window. The description reinforces that stats are scoped to a single app and a time window, but adds no syntax or format detail beyond the schema — baseline 3 applies.

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+resource ('statistics for a single source app') and enumerates the metrics returned (total clips, content-type breakdown, first/last seen, favorites, copies). It does not explicitly contrast with siblings such as eve_categories or eve_activity, so scope-vs-alternative is left partly implicit.

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 quoted example ('how much did I copy from Safari this month') gives a concrete scenario that maps both parameters to a real question. There are no exclusions or explicit alternatives, so the agent must infer when a different sibling (e.g. eve_activity) is the better call.

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