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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed-world scope, so the safety profile is covered. The description adds the account scoping ('caller's account') and the shape of the events, but says nothing about ordering, pagination beyond the schema's limit, or whether results are truncated events versus aggregated counts.

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 sentence with the verb front-loaded and no redundant filler. The only soft spot is the vague qualifier 'recent', which adds ambiguity rather than information given the explicit start/end parameters.

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?

With a full output schema, complete parameter documentation and rich annotations, the description does not need to explain return values. It is nevertheless thin on behavior an agent might care about, such as default ordering or how omitted time bounds are interpreted, leaving the definition merely adequate for its complexity.

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 100%, with start, end and limit each documented including defaults and bounds, so the schema carries parameter meaning. The description only weakly reinforces this by calling the events 'recent', which does not clarify how start/end interact or what happens when they are omitted.

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 plus resource ('List recent API usage events') and enumerates the returned fields (endpoint, method, status code, cost). That makes the tool distinguishable from resource-oriented siblings like get_analytics or get_balance without opening the schema, though it never names an alternative explicitly.

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?

There is no when-to-use guidance beyond the generic act of listing events. Nothing tells the agent how this differs from adjacent analytical tools such as get_analytics or get_change_history, and no prerequisites or exclusions are stated.

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