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

Annotations already establish readOnlyHint=true and openWorldHint=false, and the description layers on real behavioral detail: newest-first ordering, a fixed 50-per-page cap, the exact response envelope { rounds, next }, and the cursor round-trip rule with null on the final page. That is the pagination and return-shape context an agent needs and cannot get from the annotations.

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 compact sentences lead with what is returned, then the envelope, then pagination — the most useful information first. Every clause carries a fact (ordering, page size, field list, null semantics) with 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?

There is no output schema, so the description must carry the return contract, and it does: it names the envelope keys, enumerates every round field, and defines paidSol's units and null case. For a two-parameter paginated read tool, nothing an agent needs to call it correctly is missing.

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 coverage is 100%, so both mint and cursor are already documented structurally, making 3 the baseline. The description adds meaning beyond the schema by explaining that cursor is the previous page's next value and that it is null on the last page, clarifying the parameter's lifecycle rather than just its type.

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?

"A coin's rounds, newest first, 50 a page" names the resource (rounds for a coin), the ordering, and the page size, which is enough to separate it from the singular get_round. It stops short of an explicit verb or a stated contrast with get_round/search_coins, so it is clear but not fully differentiated.

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 description gives solid pagination guidance ("For older rounds, pass next back as cursor") and notes next is null on the last page. It never says when to use this list tool versus get_round for a single round or search_coins, so the when-to-use decision is only implied by the plural resource name.

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