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

With no annotations, the description carries the full disclosure burden. It usefully reveals the output content (the specific statistics computed), which substitutes partly for the missing output schema, but says nothing about read-only/safety profile, scope (whose memories, all users or the caller's), or whether results are cached or computed live.

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?

A single front-loaded sentence that enumerates the payload with no filler, hedging, or repetition of the 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 simple zero-param tool this is nearly sufficient, but with no output schema and no annotations the description is the only source of behavioral detail, and it omits scope of aggregation and how the time windows are defined (calendar vs rolling, timezone).

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, so there is nothing for the description to disambiguate beyond confirming there is no filtering or time-range input. Baseline of 4 applies for a no-parameter tool.

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 gives a concrete verb ('Get statistics') and resource ('memories') and enumerates the specific metrics returned (today/week/month totals, average days between memories, count per type). It is clearly distinguishable from search-oriented siblings, though it does not explicitly contrast with aggregating siblings like get_system_status or get_timeline.

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?

Usage is only implied: an agent can infer it is for aggregate/temporal summary rather than retrieval, but the description never states when to prefer it over get_timeline, get_recent_memories, or search_temporal, nor any conditions or exclusions.

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