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

Annotations already declare readOnly, idempotent, closed-world, non-destructive behavior, so the bar is low. The description adds real value beyond them by disclosing that the data is 'curated' rather than live, that it includes a research date, and that a missing curve is signaled with found=false rather than an error.

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 dense sentences with zero filler; the resource and key are front-loaded before the return contents and the found=false caveat. The packed list of returned fields is slightly heavy but each clause earns its place.

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 an output schema present, return values need not be re-explained, and annotations cover the safety profile; the description still adds the found=false semantics and data provenance. The only gap is how an agent obtains a valid slug or when to prefer this over the sibling listing/spec 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 100% with a single parameter, so the schema already documents 'slug'. The description only restates '(by slug)' and adds no format, casing, or sourcing detail (e.g., that the slug comes from jt_model_search), which is the baseline 3 case.

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 names a specific resource (curated pre-owned price curve for a catalog model, keyed by slug) and enumerates exactly what it returns: median/min/max, history by year, 5-year residual, research date. It is clearly distinct from sibling tools like jt_market_listings and jt_model_specs, though it never explicitly contrasts itself with them.

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 guidance versus alternatives such as jt_market_listings (live asking prices) or jt_model_specs. The 'found=false means no curated curve' note is a result condition, not usage guidance.

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