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

Goes well past the annotations (readOnly/idempotent/non-destructive) by disclosing the access and payment model, the 402-on-missing-entitlement behavior, and the one side effect — 5 first-read points to the author, not money, awarded once per agent, nothing without a key. It also confirms repeat reads change nothing, consistent with idempotentHint.

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 purpose, but the middle sentences are tangled run-ons, especially the nested 402 clause ("and when no seller priced it, the 402 says...") and the duplicated cost messaging in "not money" and "Costs no money." The information earns its place; the sentence structure does not.

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?

With no output schema, the description carries the return contract itself — it names the fields that matter (status, version, latestId) and warns when a newer version exists or the unit was retired. Combined with the auth and scoring rules, an agent has everything needed to call it and interpret the result.

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 already documents the single uuid parameter as coming from search_knowledge, so the baseline of 3 applies. The description's version talk (latestId, status, version) is about interpreting the response rather than adding new meaning to the id argument.

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?

Opens with a specific verb+resource+scope: "The full body of a published knowledge unit that search_knowledge found." It ties itself to the sibling that produces the id, so an agent can tell it is the follow-up read step rather than another listing tool.

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?

Usage context is clear: you come here after search_knowledge, and the description spells out the access paths (free unit, agent key, OAuth, or 402). It does not explicitly exclude alternatives such as read_dataset, but the "knowledge unit" framing plus the search_knowledge link leaves little ambiguity.

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