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

Annotations already cover readOnly, idempotent, and non-destructive, so the safety profile is done. The description adds genuinely new context the annotations don't carry: the operation is free, no payment occurs, and the returned quote_id is the credential for the follow-up parse_document call.

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, no filler, and the value proposition ('free', 'exact final price', 'before any payment') is front-loaded where the agent needs it.

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-value documentation isn't required, and the description still previews the key return fields and the quote_id handoff. The only gap is any precondition on the input URL, which is minor for this simple one-param tool.

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?

One parameter with 100% schema description coverage ('PDF URL'), so the schema handles the semantics. The description adds nothing about URL constraints (public accessibility, size limits), so the 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?

States a specific verb and resource (quote a PDF parse) plus what the quote contains: page count, route, and exact price. It clearly distinguishes itself from parse_document by framing itself as the free pre-payment step.

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?

Explicitly positions the tool as coming 'before any payment' and tells the agent to use the returned quote_id with parse_document. It doesn't spell out when to skip this tool (e.g., if a quote is already held), so it stops short of a full when/when-not statement.

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