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

With only readOnlyHint=false in the annotations, the description carries real weight: it discloses the two return values and their purpose, idempotency semantics, the public-https webhook requirement with concrete tunnel examples, and the crucial caveat that sandbox webhooks are real signed HTTP requests. That is exactly the beyond-annotation context an agent needs.

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?

Four tight sentences, front-loaded with the action and endpoint, then returns, then idempotency, then the webhook constraint. Every sentence carries information the agent needs and nothing is repeated from the schema.

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?

No output schema exists, yet the description names both returned values and why they matter, and it flags the non-obvious sandbox webhook behavior and idempotency. For a 6-param mutation with only a single annotation, this is complete enough to call correctly.

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 100%, so baseline is 3, but the description adds meaning on top: webhookUrl must actually reach the user's receiver via a tunnel, and externalCreatorId is the idempotency key. The remaining parameters are left to the schema, so it does not fully compensate for the interaction between externalCreatorId and idempotency.

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 ('Registers a seller (provider) under the test key') plus the endpoint POST /providers/register, and makes the sandbox scope explicit so it is distinguishable from any production provider tooling among the 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?

Explains that this is the prerequisite for creating goals (providerLinkCode is 'needed to create goals'), which implicitly routes the agent to create_test_goal, and notes idempotency on externalCreatorId so repeat calls are safe. It does not explicitly call out exclusions or name an alternative path, so it falls short of a 5.

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