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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=true, idempotentHint=false, openWorldHint=true), so the bar is lower. The description still adds real behavioral value: the timezone-awareness, the optional receptionist attachment, and crucially that informational hours do not affect DID routing.

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?

Four compact sentences front-loaded with the core action, then supporting format and routing details. Each sentence carries information, though the density makes it read more like spec notes than a guided instruction.

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 destructive, non-idempotent mutation with no output schema and zero schema coverage, the description covers the schedule semantics well but does not clarify what id/name/ivr_config_id control or what happens to existing windows not mentioned. Adequate but with notable gaps.

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% for 5 parameters, so the description must compensate. It does explain day (0=Monday to 6=Sunday), start/end (HH:MM), and that is_closed windows are date-bounded exceptions, but leaves id, name, timezone, and ivr_config_id (notably how id selects edit vs create) unexplained.

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 pair (creates or edits) and resource (timezone-aware opening-hours schedule), plus the optional receptionist attachment. It is clearly distinguishable from deletion siblings like delete_receptionist_hours and from upsert_menu/upsert_queue by naming its own resource domain.

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?

Adds routing context ('Informational receptionist hours do not change DID routing'), which hints at when hours are consequential, but never explicitly names alternatives (e.g. delete_receptionist_hours, set_number_routing) or states when-not to use it. Usage is implied rather than spelled out.

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