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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, but the description adds meaningful context beyond them: premium licensing, example return shapes, and detailed error behavior, including that malformed input returns an error object rather than raising a protocol error.

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?

The description is front-loaded with the core computation, followed by a compact example, usage guidance, exclusions, and error behavior. Every section is useful and there is no filler.

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?

Given the output schema, full parameter schema coverage, and annotations, the description provides everything needed: purpose, usage boundaries, example input/output, and error semantics. An agent can invoke and retry the tool correctly from this definition.

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%, so the schema already documents all six parameters thoroughly. The description adds value with a concrete example showing opened_at, sla_hours, and business_hours_only in context, plus the resulting mode output, though it does not need to compensate for schema gaps.

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 uses a specific verb and resource: it computes when a ticket's SLA falls due, including wall-clock versus business-hours modes. It also explicitly differentiates from deadline_planner, so an agent can distinguish it from siblings without inspecting schemas.

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?

It states exactly when to use the tool: when a response or resolution clock has started and one due moment is needed. It also states when not to use it, naming deadline_planner for multi-step project schedules.

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