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

No annotations, so the description carries the burden, and it does useful work: GET implies read-only, the x402 pricing ($0.04) signals a paid/authenticated endpoint, and the ranking/output shape is described. It stops short of disclosing pagination, rate limits, or error behavior.

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 core purpose and appropriately sized, with the HTTP/pricing metadata quarantined in a bracket. The two opening clauses are somewhat redundant ('biggest moves' vs 'where news is landing').

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?

No output schema exists, and the description sketches the return shape ('same shape as /v1/movers, ranked by absolute change with volume surge ratios'), which is adequate. However, with three of four parameters undocumented, the definition leaves real gaps 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?

Schema coverage is only 25% (just min_liquidity), so the description should compensate for window, limit, and category. It restates the window enum values (1h/6h/24h) already in the schema but says nothing about limit or the confusing category enum, which includes science-tech even though the endpoint is pre-filtered.

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: active science-tech markets ranked by absolute probability change over a window, with volume surge ratios. The phrase 'pre-filtered to science and technology markets' explicitly distinguishes it from the generic probability_movers sibling.

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 fastest way to see where news is landing in science and technology' implies the use case but never states when to prefer this over probability_movers or probability_board_science-tech. No exclusions or explicit alternative routing are given.

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