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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), so the description correctly focuses on non-obvious behavior: it counts against the client hourly MCP capacity policy and settlement differs on the paid HTTP API. This billing/capacity disclosure is genuine added value beyond structured fields; only the slightly repetitive phrasing of the policy keeps it from a 5.

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-loads purpose in the opening clause and every sentence carries information. Minor redundancy: the paid-HTTP settlement point is stated twice ('use the paid HTTP API for per-request settlement' and 'paid HTTP requests are separate from this MCP capacity policy'), and 'focused route/set' is repeated, costing a point.

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?

An output schema exists, so return-value explanation is rightly omitted, and annotations carry the safety profile. Usage, routing behavior, and billing context are all present; the only soft spot is that the dual-channel settlement message is split across two sentences, creating slight ambiguity about which channel this call uses.

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 description coverage is 100% – the 'query' param already ships with examples ('Is 0xABC safe?', 'Best yield on base?') and the 44-value chain enum is fully documented. The description restates the natural-language nature of the input but adds no format, constraint, or default detail beyond the schema, so the baseline 3 applies.

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: natural-language intent routing where the agent describes a question and ChainRay 'selects a focused set of data services.' It explicitly distinguishes itself from the sibling tool family ('For deterministic workflows, call the specific tool directly'), so an agent can tell it apart from token.risk, defi.aggregator, etc. without reading any schema.

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?

Gives clear when-to-use ('when the agent has a natural-language data question and needs ChainRay to select a focused route'), when-not ('for deterministic workflows, call the specific tool directly'), and an alternative channel (paid HTTP API for per-request settlement). All conditions are explicit rather than inferred.

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