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

Annotations already declare readOnly=false, destructive=false, idempotent=false, openWorld=false, so the safety profile is covered. The description adds that tenants map to customers and how they are subsequently referenced, but says nothing about duplicate external_id behavior, error cases, or auth requirements that a non-idempotent create would benefit from.

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 short sentences, front-loaded with the core action before the follow-up workflow. No filler, though the second sentence is somewhat terse and its "send with tenant set to its external id" phrasing is slightly cryptic.

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?

With an output schema present and annotations covering safety, the description only needs to convey purpose and next steps, which it does. Full parameter coverage in the schema closes the remaining gap, making this largely complete for a create tool.

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 documents every parameter including the enum and the "cannot be changed later" constraint on external_id. The description's mention of "external id" adds light downstream context (how the id is reused on sends) but does not meaningfully extend the schema. Baseline 3 applies.

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 tenant") and adds the scope "for one of your customers." It clearly reads as the creation counterpart to get_tenant/update_tenant/list_tenants, though it never explicitly contrasts itself with those siblings.

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 gives a post-creation workflow (send with tenant set to the external id, add domains via create_domain) and names the sibling tool for domains. However it never states when to use this vs. alternatives or any prerequisites/exclusions for creation itself; usage is implied rather than explained.

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