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

Annotations already declare readOnly/idempotent/openWorld, so the bar is lower, and the description still adds genuinely useful operational context: a per-call price of $0.001 USDC via x402 on Solana and an equivalent HTTPS endpoint. It does not describe the response payload or any failure modes.

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?

Front-loaded and brief, with cost/endpoint details trailing sensibly. However, the parenthetical 'There are 5 through 10, and 15 through 40' is ambiguous noise — it is unclear whether it refers to practical numbers, ranges, or example outputs — and distracts from the core definition.

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 one-parameter read-only count tool with no output schema, this is close to sufficient, but it never defines what a 'practical number' is nor confirms that the return value is a single count, leaving the agent to infer the output shape.

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%, but the single parameter is a self-documenting integer with min/max in the schema. The description's 'n runs from 1 to 5000' merely restates those constraints rather than adding new meaning (e.g., performance implications at large n).

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 verb and resource: counting practical numbers in the range 1..n, with the input bound spelled out. It implicitly distinguishes itself from the sibling `practical` (which presumably tests a single number), but never names that sibling 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?

The range constraint 'n runs from 1 to 5000' tells the agent when the call is valid, but there is no guidance on when to prefer this over `practical`, nor any note on what to do for numbers outside the range. Usage is only implied.

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