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 "destructive" claim adds no new information. It does add useful context about requiring explicit confirmation, but the "Side effects" line merely restates the destructive behavior already covered by annotations and the first sentence.

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 description is short and front-loaded with the core action, but the "Side effects" line is redundant with both the first sentence and the destructiveHint annotation. It contains roughly one sentence of wasted content.

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 bulk operation with full schema coverage and an output schema, the description covers the essential action, the destructive nature, and the confirmation requirement. It could be more complete by noting whether this applies to regular faxes only versus outbox faxes, but nothing critical for invoking the tool is missing.

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 the input schema fully documents fax_ids, user_id, and confirmation_text. The description does not add parameter-level meaning, but the baseline of 3 is appropriate because the schema already carries the semantic weight.

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?

The description states a specific verb and resource: "Delete multiple fax records in one request." It clearly distinguishes itself from single-delete tools like delete-fax by emphasizing the bulk nature, though it does not explicitly differentiate from the sibling bulk-delete-outbox-faxes.

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 implies usage when multiple fax records need deletion, but provides no explicit guidance about when to choose this tool over delete-fax, delete-outbox-fax, or bulk-delete-outbox-faxes. No alternatives or exclusions are mentioned.

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