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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds value by disclosing the data source (CoinGecko), the keyless/free nature, and the specific data points returned (live price, 24h volume, market cap, 7-day trend,-exchange breakdown, monthly history). No contradiction with 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?

The description is front-loaded with the core purpose and disambiguation, followed by a compact list of return values and source. Every sentence earns its place—no fluff or redundant filler. The structure is efficient and scannable.

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?

Given a parameterless tool with an output schema and annotations covering safety, the description is fully complete: it states the data source, the exclusion of ecocredit volume, the exact data returned, and points to a human-readable page for deeper history. Nothing critical is missing for correct invocation.

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?

The tool has zero parameters, so the schema is trivially covered and the description correctly skips parameter details. Baseline 4 applies for 0-param tools; the description focuses on what the tool does rather than input, which is appropriate given the parameterless context.

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?

The description states a specific action ('changes hands') on a specific resource (the $REGEN token), making the purpose unambiguous. It explicitly contrasts with Regen ecocredit retirement volume and names the sibling tools (regen_burn_tracker) to avoid confusion.

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 explicitly tells the agent when NOT to use it ('NOT Regen ecocredit retirement volume') and directs it to the correct alternative tools ('use regen_b_tracker or the commons page for that'). This gives clear selection criteria relative to siblings.

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