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

Annotations already declare this is a non-destructive, non-idempotent mutation, so the safety profile is covered. The description adds the closed_target behavior and the Business plan requirement, which is real value. It still omits what happens to prior routing (overwrite?), whether changes are immediate, and whether number vs number_id are alternatives.

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?

Three tight sentences with the action and target list front-loaded and no filler. Dense but every clause carries information.

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 an 8-parameter configuration tool with no required fields, no output schema, and no parameter documentation, the description is too thin. It should at least disambiguate the *_id vs name parameter pairs and note whether routing overwrites existing settings.

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 0% across 8 parameters, so the description carries the full burden. It explains the target values and the closed_target concept, but leaves number vs number_id, target vs target_id, auto_record, and time_group_id entirely undocumented, so an agent cannot tell how to populate most fields.

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 ('Points a number at') and enumerates the exact routing targets, so the resource and action are unambiguous. It does not name or differentiate from siblings like upsert_receptionist/upsert_queue, which define those targets rather than route to them, so it falls short of a 5.

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 a prerequisite ('A shared line, receptionist, menu, or queue needs Business'), which is useful context. However, it gives no when-to-use guidance versus the upsert_* siblings that create the receptionist/menu/queue objects this tool routes to, leaving the workflow relationship to inference.

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