activity_timeline

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

Annotations already declare readOnlyHint=true, and the description echoes this with a '[READ]' tag. The description adds the bucketing behavior (hour/day aggregation) which is useful beyond annotations, but says nothing about pagination, limits, default time range behavior, or what happens when since/until are omitted.

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?

Front-loaded purpose in one sentence followed by a short parameter list. No filler. Could be marginally tighter but earns its place.

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 3-param read-only analysis tool with no output schema, the description covers the basic contract but leaves gaps: no return shape, no default range behavior, no indication of what 'op counts' means concretely. Adequate but should do more given zero schema coverage.

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 carries the burden and does explain since/until as ISO timestamps and bucket as hour/day. However, it doesn't state the default bucket ('day' per schema), doesn't say what happens when timestamps are omitted (both default to null), and doesn't clarify timestamp format expectations beyond 'ISO'.

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 ('Op counts bucketed by hour/day') and adds a scope qualifier ('monitoring-continuity evidence'), so an agent can tell what the tool produces. It is distinguishable from siblings like query_audit_events or coverage_summary, though no sibling is named 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?

No guidance on when to use this versus query_audit_events or coverage_summary, both of which also concern audit activity. 'Monitoring-continuity evidence' hints at a use case but gives no explicit when/when-not criteria.

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