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

Annotations already cover the read-only/idempotent/closed-world profile, and the description adds genuinely new behavioral context: it is free with any API key and otherwise costs $0.01 via x402 with payment sent in _meta["x402/payment"]. This is high-value cost/auth disclosure that annotations cannot convey, though nothing is said about result cardinality or no-match 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?

Three tight sentences with the purpose and workflow role front-loaded, then pricing. No filler or restatement of the name.

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 one-parameter tool with no output schema, the description covers purpose, return fields, downstream use, and cost. Minor gaps remain around multiple matches and empty results, which matter for an agent deciding whether to trust the resolution.

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 carries the burden, and it does explain that 'query' is free text naming a compound, material, or research topic. It also clarifies the return shape (subject_type/subject_id). It adds no format or length constraints, so slightly short of full compensation.

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 ('resolve') and resource (free-text query -> subject_type/subject_id), and names the downstream sibling get_subject_ri, so an agent can tell exactly what this returns and where it fits in the workflow.

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?

Explicitly positions the tool as a prerequisite for get_subject_ri, which is clear usage context. It does not mention alternatives (e.g., when to use get_element_ri instead) or what to do when a query yields no match, so it stops short of full when/when-not guidance.

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