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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds one behavioral detail — that omitting `name` returns a listing rather than a single entry — but says nothing about result shape or limits beyond what the output schema would carry.

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?

Two sentences, front-loaded with the core purpose and the enumerated kinds, with the listing behavior in the second sentence. No filler or repetition.

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 values need not be described, and for a two-parameter reference lookup the description covers purpose and the one non-obvious calling mode. The remaining gap is sibling disambiguation against docs_search/docs_get, which matters given the crowded namespace.

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 50%, with `name` documented in-schema with examples. The description restates the kind categories that the enum already enumerates and adds the omit-to-list semantics, which is also present in the schema description, so it contributes little beyond structured data. Baseline 3 for a two-parameter tool with partial coverage.

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 ('Look up') plus a specific resource (a Total CMS reference entry) and enumerates the entry kinds covered, so the agent knows exactly what domain it serves. It does not name or differentiate itself from the many sibling lookup tools (docs_get, docs_search, describe_collection), leaving the boundary implicit.

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 only explicit usage rule is 'Omit `name` to list all entries of a kind,' which tells the agent how to widen the call into a listing. There is no statement of when to prefer this over docs_search or docs_get, so the choice among siblings is left to inference.

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