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

readOnlyHint already establishes a read-only operation, and the description adds that the data is sourced from the latest weekly market report, implying a periodic snapshot rather than a live query. No destructive side effects, auth, or rate-limit concerns are relevant for a zero-argument read-only tool.

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?

One sentence, front-loaded with the key value ('how many diamonds and retailers'), and no filler.

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?

For a zero-parameter read-only tool, the description fully conveys what the agent should expect: aggregate counts from a weekly report. No output schema exists, but the expected output shape is simple and sufficiently described.

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?

There are no parameters and the schema is fully self-explanatory, so the baseline is 4. The description accurately reflects that the tool provides aggregate counts without needing any inputs.

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 outcome: report the number of diamonds and retailers Carat Hunter tracks. It differentiates itself from item-level siblings like get_diamond, search_diamonds, and price_check by offering a market-level summary.

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?

The intended use is implied by the market-overview context, but the description never explicitly says when to choose this over the sibling tools. It provides no exclusions such as 'use search_diamonds for individual stones' or 'use price_check for pricing.'

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