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

Annotations already declare readOnlyHint=false and destructiveHint=true, so safety is partly covered. The description adds genuinely useful context beyond the annotations: credentials become visible in the AI conversation context (a security caveat an agent must surface), plus the authentication/session prerequisite. It does not explain storage durability or whether re-storing overwrites.

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 blocks, purpose front-loaded ahead of the caveat and access requirements. The 'Note:' and ACCESS run-on are slightly chatty but nothing is wasted.

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 is needed for a store operation, and annotations carry the safety profile. With a nested credential object and a security/privacy caveat, the description covers what an agent needs to call it correctly; only sibling differentiation and overwrite/return behavior are absent.

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%, with provider and credentials both documented inline including examples and a nested arbitrary-key object. The description adds no additional meaning about accepted provider identifiers or expected credential keys, so 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?

Clear verb+resource: 'Store DNS provider credentials for automated domain verification' tells the agent exactly what is persisted and why. It does not, however, distinguish itself from near-siblings such as connect_dns_provider, add_verification_provider, or verify_domain_with_credentials, so the agent cannot route on the description alone.

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 access note gives a real precondition (Proof account + authenticate via /mcp or start_login) which is actionable usage guidance. But there is no guidance on when to choose this tool over the other credential/connection tools, and no explicit when-not-to-use.

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