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

Annotations already mark readOnlyHint=true, but the description adds valuable context: no translation occurs, no charge is incurred, and the quote is meant to be compared against the account balance. This goes beyond the annotations without contradicting them.

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?

One dense sentence with no filler. The core action and key constraints (free, no translation, compare with balance) are front-loaded, and every clause earns its place.

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?

The full schema descriptions plus annotations give an agent enough to call this safely. The description supplies the missing context about cost, charge, and balance comparison. The lack of an output schema is the main gap, but the title and description make the returned credit price reasonably clear.

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 baseline of 3 applies. The description adds no parameter-specific detail; it only mentions credits and balance generically, while the schema thoroughly documents all seven parameters.

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 ('Price'), a resource ('a document'), and the scope: in credits, without translating or charging, and comparing with the account balance. This clearly distinguishes it from translation tools and from get_credit_balance at a glance.

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?

Clearly communicates this is a free pre-flight estimate ('without translating or charging anything') and that it should be compared with the account balance. However, it does not explicitly name a sibling alternative or state 'use this when you only need an estimate before translating,' so it stops short of fully explicit routing.

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