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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write, so the safety profile is covered. The description adds a trait the annotations do not carry: the required service_areas:write scope, plus the fact that the created entity is incomplete until link records are added. It does not describe the return payload, but that gap is minor against annotations that already carry the mutation profile.

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 sentences, no filler. Purpose comes first, then the auth requirement, then the follow-up workflow, in the order an agent needs them. Nothing repeats the structured fields.

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?

Covers purpose, permission requirement, and the post-create linking steps for a tool with full schema coverage and no output schema. The one remaining gap is that it tells the agent to link system classes and sites via follow-up tools without indicating whether the newly created service area's identifier is returned, which the agent needs to pass to those calls.

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% across all six parameters, each with its own description, format hint, and constraints, so the schema does the heavy lifting. The description adds no parameter-level detail (e.g., uniqueness of name, default of is_active) beyond what is already documented, which is the baseline 3 case.

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 ('Create a new service area') and scopes it to Level of Service tracking, which separates it from the adjacent link-table tools create_service_area_site and create_service_area_system_class that the description explicitly routes to. An agent can identify this as the parent-entity creation call without opening the schema.

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?

Supplies the sequencing context an agent actually needs: creation alone is incomplete, and subsequent links must be made via create_service_area_system_class and create_service_area_site by name. It stops short of stating when not to create a service area or what to do if one already exists, so it is clear context rather than explicit when/when-not guidance.

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