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

Annotations already declare this as a safe, read-only, idempotent, non-destructive lookup, so the description needn't restate safety. It adds real context by disclosing the subject matter covered — service fee, credit tiers, allowed terms — which signals this is a static policy reference with no side effects. It does not describe the shape of the returned guidance, but the zero-parameter, closed-world nature limits that concern.

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 short sentences, content list first and usage trigger second, with no filler. The only minor weakness is that the 'what an assistant can do / what the buyer must do personally' phrasing is dense and could be read as describing the tool's own capabilities rather than its contents.

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 zero-parameter, read-only informational tool with no output schema, the description covers what is inside and when to fetch it, which is enough for correct invocation. A note that it returns static guidance (rather than live pricing or inventory) would fully close the gap against find_cars and get_payment.

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 tool takes no parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly implies a context-free call with no arguments needed.

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 names the exact content the tool returns — assistant-vs-buyer responsibilities, service fee, credit tiers, allowed terms — so an agent knows this is a process/policy reference rather than a search or payment action. It does not name or differentiate itself from siblings find_cars and get_payment, leaving the agent to infer the boundary.

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?

"Use it at the start of a conversation about buying a car" gives a clear triggering condition. There are no explicit exclusions or pointers to alternatives (e.g. 'do not use for pricing lookups, use get_payment'), so routing against siblings is only partially supported.

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