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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the safety profile is covered structurally. The description earns credit by adding real behavioral context beyond that: ai_receptionist 'rings the seat first, then hands the call to the AI receptionist or phone menu in menu_id', and the '(Business)' marker flags a plan requirement. It does not, however, spell out that this overwrites existing handling for the given `when` condition.

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?

Two dense sentences with no filler, front-loaded with the trigger conditions and then the action vocabulary. The second sentence is a run-on that mixes the ring-flow behavior with the menu_id reference and the '(Business)' tag, slightly hurting scannability.

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-parameter mutation tool with no output schema, the description covers the trigger set, the full action vocabulary, the menu_id link and a plan restriction, with annotations carrying the destructive/idempotent profile. The remaining gap is overwrite semantics for previously configured handling, which an agent would want to know before calling.

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 only 33% (only menu_id is documented), so the description must compensate, and it largely does: the sentence 'when this seat declines a call, does not answer it, or is busy' maps one-to-one onto the `when` enum, and the listed values map onto the `action` enum. The dependence of menu_id on the ai_receptionist action is also restated, though the description never says which actions ignore menu_id.

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 states a specific verb and resource ('Sets what happens when this seat declines a call, does not answer it, or is busy') and enumerates the exact action values it accepts. It is clearly distinguishable as a per-seat call-handling policy setter, though it never names or contrasts the nearest siblings such as set_number_routing or update_forwarding.

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?

Usage is implied by the trigger conditions ('declines a call, does not answer it, or is busy'), so an agent can infer it applies to seat-level unanswered-call handling. However, there is no explicit when-to-use versus alternatives guidance and no stated prerequisites beyond the parenthetical '(Business)' on ai_receptionist.

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