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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is covered. The description adds real value beyond that: it discloses the downstream effect on domain verification and the authentication prerequisite, including the session flow via start_login and the /mcp authenticate step.

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?

The destructive effect is front-loaded in the first two sentences, with the auth instructions clearly separated. The auth paragraph is a bit long but every line conveys actionable information about how to obtain access.

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 one-parameter destructive tool with no output schema, this covers the essential concerns: what is destroyed, the downstream impact, and how to authenticate. Nothing critical is missing, though explicit routing to sibling tools could improve it.

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?

Only one parameter ('id') and schema description coverage is 100%, so the schema already documents it fully. The description adds no additional meaning about the id format or source, matching the baseline 3 for schema-documented params.

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 ('Delete a stored DNS provider credential'), which is distinguishable from create_dns_credential, list_dns_credentials, and check_domain_credentials. It does not explicitly name those siblings, so it falls short of a 5.

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 description explains the consequence of deletion (affected domains need new credentials for automated verification), which implies when the tool matters, but it never states when to use this versus alternatives or prerequisites for choosing a credential to delete. Usage is implied rather than directed.

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