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

Beyond the annotations, the description adds critical safety context: the action costs money, cannot be undone, only happens after deliberately paying a returned link, and the tool itself does not charge. This is rich behavioral disclosure with no contradiction to annotations.

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 three sentences with the key function front-loaded. The cost warning is repeated across sentences, but this is deliberate emphasis for a risky action rather than unnecessary filler.

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 tool with no output schema, the description covers prerequisites (a prior quote), what the tool returns (price and payment link), and what happens next (fax sent only after paying). Nothing needed for correct invocation or risk assessment 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?

The single parameter quote_id is already fully described in the schema with 'A quote_id from quote_fax.' The description reinforces the 'previously quoted' requirement but adds no new format or semantic details beyond the schema, 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?

The description states a specific verb ('returns') and resource ('authorization instructions for sending a previously quoted fax'), and immediately clarifies that the tool does not actually send the fax. This distinguishes it from the title and from siblings like quote_fax.

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 clearly scopes usage to a previously quoted faxage and the schema requires a quote_id from quote_fax, so an agent knows this tool is used after quote_fax. It does not explicitly name alternative tools, but the sequencing is clear enough.

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