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

Annotations already declare idempotentHint=true and destructiveHint=true; the description adds the crucial non-obvious behavior that the response means queued, not delivered, plus the "Scope: fax:send" auth requirement and idempotency semantics. It does not clarify reversibility (cancel_fax exists but isn't mentioned), which matters given destructiveHint=true, so it misses one meaningful disclosure.

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 dense sentences, each carrying distinct load: purpose, authorization branching, idempotency, async semantics, and scope. No filler and the primary action is front-loaded in the first clause.

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?

An output schema exists so return values need no explanation, and the description covers the authorization preconditions, async behavior, and follow-up tool well. It is incomplete on client_reference and on how the quote_id is obtained, which an agent must resolve from sibling tools.

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?

With 0% schema coverage the description carries the full burden, and it does explain approval_id (an approved request bound to this quote) and idempotency_key (same key returns the same fax). However, the fourth parameter, client_reference, is never mentioned, and quote_id's provenance (obtained from quote_fax) is only implied.

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?

"Queue a quoted fax" gives a specific verb (queue) and resource (fax), and the quote_id requirement implicitly separates it from quote_fax and prepare_fax. It stops short of naming the sibling that creates the quote the agent must already hold, so differentiation is inferred rather than stated.

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?

It lays out explicit routing logic: if authorization_required=false send as is, otherwise supply an approval_id from request_human_review, or use a delegated policy that permits it. It also names the mandatory follow-up (poll get_fax_status), so the agent knows both when to call this and what to do next.

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