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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description's added value is the concrete domain-specific consequence: deleting MX/SPF/DKIM/DMARC stops mailboxes working. It does not say whether deletion is permanent/reversible or whether confirmation is required, which is the main remaining gap for a destructive op.

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 sentences, zero waste: the operation and id source come first, the risk warning second. Every clause carries actionable information.

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 destructive, no-output-schema tool this covers operation, identifier source, and consequence. Missing only reversibility/confirm behavior, but annotations already carry the destructive profile, so an agent has enough to call it 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?

At 50% schema coverage, 'domain' is documented in the schema while 'record_id' has only a type. The description compensates for exactly that gap by explaining the provenance of the id (obtained from list_dns_records), which is the non-obvious part an agent must know. It adds no format details beyond that.

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?

Specific verb + resource + identifier basis: 'Delete a DNS record by id'. It also names the sibling (list_dns_records) that produces the id, distinguishing it cleanly from add_dns_record and list_dns_records.

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?

Tells the agent where to get the required record_id ('from list_dns_records') and flags the high-risk record types where deletion breaks mail. It stops short of stating prerequisites (e.g. domain must be in the account) or an alternative to deleting, but the use context is clear.

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