dv_rank

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds one genuinely useful non-annotation fact — that monthly_deposit_rate is an assumption rather than a market fact, and that only 'supported' price evidence is used. It says nothing about the ranking algorithm, tie-breaking, or determinism, so credit stops at 3.

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 tight sentences with no waste; the ranking basis is front-loaded and the caveat follows. Efficient and readable, though the terseness is partly why key semantics (mode) go unexplained rather than because everything necessary was said.

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?

This is a high-complexity tool: a nested SearchRequest with dozens of fields (price/deposit bounds, filters, constraints, sort, strict), a mode enum, and a nested data type. With 0% schema coverage and an output schema present (so return values need not be explained), the description still omits the mode semantics and the dependency on a prior search. For this complexity, it is substantially under-specified.

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%, so the description carries the full burden and largely fails it. It clarifies only monthly_deposit_rate (an assumption), while the four mode enum values (best_fit, best_value, cheapest, deals) — the primary control over behavior — are never mentioned or explained, nor is the request/constraints structure. Only one of three top-level params gets any semantic help.

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 the verb 'rank' and the basis ('explicit preferences and supported price evidence'), which is more specific than a tautology. However, the resource is described only as 'the scanned sample', an unexplained term — it never says what entity is being ranked (listings?) or where the sample came from. Adequate but leaves the agent guessing at the object of the operation.

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?

No when-to-use guidance and no routing to alternatives, despite 30+ siblings including dv_search, dv_compare, dv_assess_price and dv_similar that an agent must choose between. It does not say whether a prior scan/search is a prerequisite or how ranking relates to comparison. Nothing beyond an implicit 'use this to rank'.

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