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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered structurally. The description adds nothing beyond that: it does not say the tool is a pure offline calculation, what assumptions/units it uses, or whether the result is a single figure or a breakdown.

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?

A single front-loaded sentence with zero filler; the comparison at stake is stated up front. It is efficient, though arguably under-sized for a six-parameter calculation tool.

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 six required parameters, 17% schema coverage, a nested object, and no output schema, the description should carry far more explanatory weight. One sentence leaves the agent without enough information to populate or interpret this tool confidently.

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 only 17% — just one of six required parameters (autoModelMix) is documented, and its 'must sum to 1' constraint lives only in the schema. The description does not clarify units (tokens vs. thousands), the valid form of pinnedModelId, or the meaning of workDaysPerMonth, so it fails to compensate for the coverage gap.

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 gives a specific verb ('Estimate') and a concrete comparison ('Cursor Auto blended cost versus pinning a single model'), which is more informative than the title alone. It does not, however, distinguish itself from the adjacent cost tools (agent_cost_estimate, swarm_run_cost_estimate) that occupy the same sibling namespace.

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 when-to-use guidance, no statement of prerequisites, and no routing away from the two sibling cost estimators. An agent has to guess which of the three cost tools is appropriate for a given request.

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