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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world call, so the safety profile is covered. The description usefully adds that the figure is a median derived from similar listings (an estimate, not an exact value), but says nothing about caching, sample size, or data freshness.

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?

The core definition is front-loaded before the granularity explanation, and the sentence count is low. The em-dash construction is dense 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 does state what the tool returns (a median day count), and it covers the granularity semantics. It is adequate for a two-parameter read-only metric tool, though it omits anything about the response shape or units.

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 must carry the parameter burden. It does explain all three granularity enum values with real meaning (same model+year, all years, same state), which is genuine added value, but the required car_id is never described and no interaction between the two params is clarified.

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 states a specific metric (median days listings stay active before being delisted) and frames it as a liquidity/time-to-sell estimate, which is more precise than the title. It does not explicitly contrast itself with siblings like get_market_stats or get_market_position, 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?

Usage is implied through the 'liquidity estimate' framing, but there is no statement of when to prefer this tool over get_market_stats or get_similar_active_listings, and no prerequisites or exclusions are given.

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