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

Annotations cover the safety profile (readOnlyHint=false, idempotentHint=true), but the description adds substantial behavior beyond them: funds are reserved up front, there is no online payment or credit path, insufficient balance requires pausing for the administrator, and retries must reuse the same key. This is exactly the context a paid mutation tool needs.

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?

Three sentences, front-loaded with what happens (paid observation + fund reservation) before the preconditions and failure handling. Every clause carries operational meaning; nothing is padding.

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 no-output-schema, four-required-parameter mutation tool, the description covers auth (API Key, geo:run grant), preconditions, funding behavior, failure recovery, and idempotency. It doesn't say what a successful call returns (e.g., an observation id) for the agent to act on next, which is the only meaningful omission.

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 0%, so the description must carry the load, and it names all four parameters and their semantics: approved must be true, idempotency_key must be stable and reused across retries, max_charge_cents is the approved upper bound, quote_id ties to the accepted quote. The only gap is that it doesn't state the charge ceiling or the key's length/character constraints that the schema enforces.

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 ('Starts a PAID asynchronous observation') plus the side effect ('reserves funds'), which distinguishes it immediately from siblings like geo_quote_observation and geo_cancel_observation. An agent knows this is the commit/accept step of the quote flow without opening any schema.

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?

Gives an explicit precondition ('only after the customer approved this quote and maximum charge'), a named fallback path on failure (read payment_handoff and pause), and a retry rule ('retry the same request with the same key'). It also states exclusions: no online payment, no automatic credit, no silent target switch, no budget increase, no recurring schedule.

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