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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=false and openWorldHint=true, covering the write/safety profile. The description adds genuinely new behavior — the duplicate-myId refusal returns an error and nothing is created — but says nothing about auth requirements, side effects on the parent site/customer, or the response.

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 clauses with the operation type front-loaded as 'WRITE:' and the key constraint in parentheses. No filler; every clause carries a rule the agent needs.

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 nested-object create tool with no output schema and annotations covering the write/safety profile, the description covers the two things an agent would most likely get wrong (the site/customer exclusivity and duplicate myId). It omits permissions and return shape, which are minor given the rich schema.

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 each field is already documented at the parameter level (including the nested 'exactly one of id or myId' rules). The description adds the cross-field constraint that site and customer are mutually exclusive, which is real added meaning, but it doesn't explain the required 'name' or the my_id semantics.

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 piece of equipment') plus where it lives (under a site or a customer), and even names the endpoint. It is clearly distinguishable from the get/list/update siblings, though it never explicitly names a sibling to differentiate against.

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?

Gives explicit applicability constraints: exactly one of site or customer must be supplied and both is refused, and a duplicate myId short-circuits with an error. It stops short of naming alternative tools or when not to create at all.

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