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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds that requests may be past or future dates and gives the valid range, but says nothing about how the 'fair' value and band are computed or whether they extrapolate beyond historical data.

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?

Two short sentences, output described first and the parameter constraint second, with no filler. Slightly better structure would put the format/range note before enumerating return components, but nothing is wasted.

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 retrieval tool with no output schema, the description adequately covers what is returned (value and band) and the legal input range. Only a brief note on band meaning or data freshness would make it fully complete.

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 0% and the single parameter has only a generic 'Date' title, so the description carries the load: it specifies the YYYY-MM-DD format, UTC timezone, and the exact accepted bounds 2010-07-18 to 2100-12-31. This is genuinely necessary information not present in 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 concrete verb and resource: retrieving the power-law trend value plus lower/upper band for a given date. That is distinguishable from siblings like explain_power_law_model and when_will_bitcoin_reach, though the description never names those alternatives to sharpen the contrast.

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?

There is no explicit when-to-use guidance, no prerequisites, and no routing to the sibling tools (e.g. when_will_bitcoin_reach for target-price questions). Usage is only implied by the word 'trend' and the accepted date range.

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