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

Annotations already cover readOnly/idempotent/non-destructive/closed-world, so the bar is lower, and the description still adds genuine policy: omitted scope is treated as unclear and never assumed included, unpriced work makes the projected range incomplete, and the tool refuses fairness verdicts. These are real interpretive behaviors an agent could not infer. It stops short of saying what the response object actually contains.

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?

Four tight sentences with the core action and privacy posture front-loaded; no filler. Phrasing is slightly telegraphic ('Report unpriced risks; the projected range is incomplete when unpriced work remains'), which costs a bit of readability but not space.

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?

No output schema exists, so the description must signal the return shape, and it does: a projected range plus questions to ask the seller plus flagged unpriced risks. The 25% schema coverage and undocumented productType/sizeClass keep it from being fully complete.

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 25% — just the nested scope object is documented. The description mentions 'total' and 'scope' but says nothing about productType or sizeClass, and given two bare enum params with no description, it does not fully 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?

States a specific verb and resource: checking a quoted total plus scope for missing costs, and produces questions for the seller. That is clearly distinct from estimate_sauna_total_cost or compare_sauna_brands, but the description never names those siblings, so the differentiation is inferred rather than stated.

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?

Usage is implied by 'check a quote' (you must already have a quote) and bounded negatively by 'does not declare a seller fair or overpriced,' plus the no-upload note. But there is no explicit 'use this instead of estimate_sauna_total_cost when...' routing, which is the key ambiguity given six sibling tools in the same domain.

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