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

Annotations already declare readOnlyHint/idempotent/non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: it discloses the underlying model (live chain difficulty, tail-emission reward) and enumerates the returned fields, which is meaningful since no output schema exists. It stops short of stating caching/liveness of the chain data or any rate limits, so not a full 5.

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 with the capability, then clearly segmented into 'When to use', 'Do not use', and 'Returns'. No filler sentences; the Returns block earns its place because there is no output schema.

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 pure read-only computation tool with no output schema, the description covers what it computes, when to use it, when not to, and what it returns. Nothing an agent needs to invoke 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 description coverage is 100%, so the baseline is 3. The description implies which inputs matter (hashrate, power price, hardware cost for ROI) but does not clarify the mutual-exclusivity of hashrate_hs/hashrate_khs/hashrate_mhs or default behavior when everything is optional, adding little beyond the schema.

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+resource ('Mining profitability calculator') and immediately qualifies it with the data sources ('live chain difficulty and the Monero tail-emission reward'), which distinguishes it from the read-only chain-data siblings like xmr_get_network_stats. The enumerated outputs (gross XMR, power cost, net USD profit, break-even prices, ROI days) make the tool's scope unambiguous.

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?

Has explicit 'When to use' (decide whether a hashrate is worth running, explain economics changes) and explicit 'Do not use' exclusions (pool share accounting, price prediction). This routes the agent away from misusing it as a pool-accounting or forecasting tool, which is exactly the disambiguation a calculator needs.

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