Sold comparisons

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

Annotations already establish read-only, idempotent, open-world behavior, so the description's job is additive — and it delivers: the data source (eBay blended sold comps), the plan tier requirement, and per-call unit cost. It does not describe the shape or volume of results, which would have pushed this higher.

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?

Three short sentences, zero filler, and the substantive definition ('what buyers actually paid on eBay') is front-loaded before the access constraints. 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?

Covers the sourcing, gating, and cost dimensions well, but with no output schema and two undocumented parameters, an agent still lacks detail on what a 'blended' comp set contains, how grades/languages alter results, and what the response looks like. Adequate but with visible gaps.

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 50%, and the description explains none of the parameters. 'grade', 'language', and 'currency' (default eur, enum in schema) carry no meaning beyond the schema, and only card_id has a description. The description does not 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 resource and scope: eBay sold comps ('what buyers actually paid ... blended sold comps') for a card. Clearly distinct from flipzi_get_price and flipzi_get_history in intent, though it stops short of naming those siblings explicitly.

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?

Gives access prerequisites (pro plan or higher) and a cost (1 unit), which is useful gating context, but says nothing about when to prefer this over flipzi_get_price, flipzi_get_history, or flipzi_get_movers. Usage is implied by the resource name only.

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