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

Annotations only declare readOnlyHint=false and openWorldHint=true; the description adds real value on top by stating that credentials stay server-side (auth handling) and that mutations are two-step (preview then confirm). It does not disclose what a mutation affects or what errors look like, but the annotated safety bar is already met and the added auth plus confirmation context is exactly the kind of detail the annotations omit.

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 short sentences with no filler, and the resource identification and credential note come first. Slightly under-specified rather than padded, so the constraint is completeness, not verbosity.

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 11 parameters, a generic body passthrough, no output schema, and many near-identical sibling proxies, the description should say which operations are supported and roughly what comes back. The fully documented schema compensates for the parameter side, but the operation scope and sibling differentiation gaps remain.

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 parameters like method, body, confirmationToken, fetchAll, and contentType are already documented in the schema. The description adds no parameter-level meaning beyond that, which is the expected baseline when the schema carries the load.

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?

"Amazon Ads: sp/campaigns API" names a resource but no verb and no operation scope, so an agent cannot tell whether this creates, updates, or lists campaigns. It is further blurred by siblings such as sp_campaigns_list and the two hashed sp_campaig_* variants, which the description does nothing to distinguish. Purpose is inferable at a high level but not actionable on its own.

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?

The only routing guidance is "Mutations require preview and confirmation," which describes a workflow step rather than when to pick this tool over sp_campaigns_list or the other sp_campaig_* proxies. There is no statement of when-not-to-use, no prerequisites, and no named alternative.

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