Get Oncall Handoff Summary

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds meaningful beyond-annotation context: the performance tradeoff of include_incidents ('slower' vs 'faster') and the semantic nuance that `role` is the On-Call role while shifts carry none. These are useful behavioral details, though return-shape/pagination is left to the output schema.

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?

Purpose and the include_incidents note are front-loaded, and the filter_by_region example is well-placed. The four-item 'Useful for' list is slightly padding-like and overlaps the usage guidance, but overall the text is organized and readable.

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 an output schema covering return values and annotations covering the safety profile, the description supplies the operational nuance an agent needs (regional filtering, incident-fetch cost, role semantics). The only gap is no explicit sibling disambiguation, but nothing essential for correct invocation is missing.

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 already 100%, so the baseline is 3; the description still adds value by giving a concrete example of timezone+filter_by_region interaction ('Asia/Tokyo' shows only APAC business-hours on-call) and clarifying the speed impact of include_incidents. It does not explain team_ids or schedule_ids beyond the schema.

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 and resource ('get current on-call handoff summary') and defines the content ('who's currently on-call and who's next'), which is concrete enough for an agent to grasp the scope. It does not, however, differentiate itself from closely-named siblings like get_oncall_schedule_summary or check_responder_availability, so the agent must infer the boundary.

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?

Provides explicit context via the 'Useful for' list (handoff meetings, regional status, cross-timezone coordination) and explains the trigger conditions for optional flags (include_incidents=True is slower; filter_by_region=True needs a timezone). It lacks explicit when-not or alternative-tool routing, keeping it below a 5.

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