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

Although annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, the description adds valuable context: 'read-only and idempotent with no destructive side effects; it performs no live exchange fetches, order placement, or settlement flows.' This goes beyond annotations by explicitly reassuring the agent that no live market interactions occur, which is important for a ranking tool. It also mentions 'latest persisted market_alpha row' and output fields, further clarifying 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?

The description is three sentences: purpose, return shape, and parameters/behavior. It is front-loaded with the most important information, and every sentence earns its place. No unnecessary detail or repetition of the title.

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?

The description covers the tool's core function, output structure, filter options, and safety profile. Since an output schema exists, return values are already documented, so the description does not need to list every field. It is sufficiently complete for an agent to decide when and how to invoke this tool, given the rich schema and annotations.

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% and every parameter has a description. The description simply lists the parameter groups ('optional product or underlying_ticker filters, source_date or source_date_from/source_date_to, mode=compact|full, limit, and offset') without adding new meaning or clarifying relationships beyond the schema. This meets the baseline but does not elevate it.

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 clearly states the tool's purpose: 'rank Coinbase INTX perp products by the latest persisted market_alpha row per product.' It uses a specific verb ('rank') and resource ('Coinbase INTX perp products'), and the unique focus on 'latest persisted market_alpha row' and the ranking board output distinguishes it from siblings like deltasignal_coinbase_perp_factors or peer_ranking.

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 provides clear context by saying 'Use this read-only tool to rank...' and enumerates optional filters and modes, implying when it's appropriate. It does not explicitly name alternatives or exclusions (e.g., when to use a different rankings tool), but the context is sufficient for an agent to infer typical use cases.

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