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

The description goes well beyond the readOnlyHint/openWorldHint annotations by disclosing basket construction (equal-weight, fixed), rebasing baseline (100 on 2025-01-01), available return windows (1d/7d/30d/90d/YTD), benchmark comparison (vs BTC), member lists, and the conditional omission of daily points unless include_points is true. This gives an agent an accurate behavioral model before calling.

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 sentences, front-loaded with the invocation conditions, then a compact enumeration of output contents. No filler or repetition of annotation-provided safety details. Every clause contributes decision-relevant information.

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 read-only tool with a single optional boolean parameter and no output schema, the description covers the essential return contents: which indices, rebase/return periods, benchmark, member lists, and when daily points appear. There is no missing detail an agent needs to call or interpret the result reliably.

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 the schema already documents include_points, but the description adds meaning beyond the schema by stating that daily points are omitted by default and included only when the flag is true. The schema's 'large' warning is reinforced by the tool description, improving the agent's ability to decide whether to set the flag.

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 names a specific resource ('eight equal-weight fixed-basket indices') and gives concrete trigger scenarios: user asks which crypto narrative/sector is leading, rotation among the listed themes, or a theme index. It distinguishes this from sibling tools by naming the thematic categories (AI, RWA, DePIN, meme, L1, L2, DeFi, quantum), which no sibling tool title covers.

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 opens with explicit call conditions: 'Call this when the user asks which crypto narrative or sector is leading, about rotation... or for a theme index.' This is strong when-to-use guidance, but it does not explicitly state when not to use this tool or name alternatives, so it falls short of a 5.

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