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

Annotations already declare readOnlyHint/idempotentHint, so the description's real contribution is the auth tier ('Requires a Personal+ account') and the payment protocol details (USDC on Base or Solana via x402, _meta["x402/payment"]), which are valuable and non-obvious. It doesn't disclose response size or pagination expectations for a full-history payload.

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?

Three dense sentences: capability, account requirement, payment fallback with exact mechanism. Front-loaded with the core purpose and zero filler.

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, so the description would ideally say what 'RIS/HRI history' returns structurally (per-year values, formatting). It covers access/payment completely but leaves the returned data shape implicit for a full-history read.

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 0%, so the description must compensate; it clarifies the resolution choices (yearly/monthly) and that subject_type is keyword/sector, but subject_id is never explained (ID format, where to obtain it) despite being required.

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 resource (yearly/monthly RIS/HRI history) and scope (one topic/keyword/sector), which is more precise than the title alone. It doesn't explicitly differentiate itself from siblings like get_subject_ri or get_subject_papers, but the 'history' framing is a distinguishable verb+resource.

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 access conditions (Personal+ account required, or pay-per-call via x402) but never says when to choose this over get_subject_ri/get_subject_papers or when yearly vs monthly is appropriate. Usage is implied rather than guided.

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