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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely new context: "It charges nothing" (no billing side effect), the refund-negotiation shape of the result, the per-case-service fallback, and the warning that the platform, not the agent, makes the final decision. That is meaningful behavioral disclosure beyond the structured fields.

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, no filler, with the payoff (pricing plus start_url) front-loaded before the edge case and the cautionary note. The first sentence is a dense comma-list of returned fields, but every clause carries information.

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?

With no output schema, the description carries the burden of explaining returns and does so (price, tier, refund terms, decision maker, start_url), plus the cost profile and the per-case-service exception. Only missing is any hint about the response envelope or whether pricing can be stale/subject to change, which would round out a pricing tool with no output schema.

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% – both `id` (with examples) and the optional `tier` are fully documented in the schema, including the pointer to list_services as the id source. The description adds no parameter syntax or format detail beyond that, 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+resource ("price of 1 service") and enumerates exactly what is returned: price, tier price, refund terms, decision maker, and start_url. It implies a distinction from quote_placements by scoping to a single service rather than placements, but never names the sibling outright, so an agent must still 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?

The description conveys implied context (call it when you need a service price) and one conditional routing rule (per-case services return the free assessment page instead), plus agent-facing guidance ("Never promise the outcome"). It stops short of any explicit when-to-use-this-vs-alternative instruction, so the agent must infer the choice against quote_placements and the check_* siblings.

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