get_usage_history

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 what is returned (delivery counts and failure rates), which is useful, but 'past periods' is vague — no default window, granularity, or aggregation semantics — and there is no output schema to fall back on.

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 with no waste. The only weakness is that 'over past periods' is under-specified rather than verbose, which costs a little clarity.

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-param read tool this is close to sufficient, and it names the two returned metrics. However, with no annotations, no output schema, and no siblings referenced, the description leaves the time window, granularity, and result shape unresolved.

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 the baseline is 4. Nothing in the description is needed to explain inputs, and it correctly implies the query is unbounded/fixed-window rather than parameterized.

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 clear verb+resource ('Get historical delivery counts and failure rates') with a scoping phrase ('over past periods'). It distinguishes itself from the live/real-time siblings only implicitly via 'historical'; the numerous get_usage* siblings (get_usage, get_usage_hourly, get_usage_latency, get_usage_by_feed) are not named.

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?

'Historical' and 'past periods' imply it is the retrospective counterpart to get_live_session and get_usage_hourly, so the when-to-use is inferable. No explicit when/when-not rules and no alternatives are named, leaving the agent to guess against six sibling usage tools.

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