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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds two genuinely useful bits of context: the estimate uses the org's real token volumes (not hypothetical) and applies standard rates, implying negotiated discounts are excluded. It does not say whether historical data availability affects the result or how partial windows are handled.

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 sentence, front-loaded with the key distinction, with no filler. Brevity is appropriate here; the shortfall is missing content rather than wasted words.

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 output schema relieves the description of explaining return values, and annotations cover safety. But for a 4-parameter tool with zero schema description coverage, the definition leaves the meaning of days, feature and from_model unstated and gives no guidance on when to prefer this over sibling estimation tools.

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% and the description only gestures at to_model ("another model"). The required from_model and especially days (1-90, default 30) and feature are entirely unexplained, forcing the agent to interpret a bare JSON schema.

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?

A specific verb ("re-prices") and resource ("the organization's real token volumes on another model") makes clear this is a cost what-if based on actual usage, not a generic model comparison. It implicitly distinguishes itself from compare_models and simulate_workload, though it never names them, so an agent must 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?

There is no explicit when-to-use statement and no routing to alternatives, despite siblings like compare_models and simulate_workload that plausibly overlap. The agent must guess whether this is the right tool for a pricing question versus a side-by-side model comparison.

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