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

readOnlyHint=true already establishes the safety profile, and the description confirms it is a pure listing operation returning spl_version + published_date pairs. It does not mention pagination behavior or ordering, but with annotations covering safety and the schema covering paging, a 3 is appropriate.

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 tight sentences: the first front-loads the returned shape and the resource, the second adds the use case and the underlying API endpoint. No 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 usefully names the return fields (spl_version, published_date), and paging is fully covered by the schema. Only minor gaps remain (ordering, whether all versions are guaranteed).

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% (setid UUID pattern, page, pagesize with defaults/max all documented), so the baseline is 3. The description re-states that setid is a label SETID but adds no syntax or paging guidance beyond the schema.

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 and resource ('List every published version (spl_version + published_date) of a label for a SETID'), names the exact fields returned, and is clearly distinct from sibling dailymed_get_label (single current label) and dailymed_search_labels (search). An agent can tell what this returns without opening the 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?

'useful to see how a drug's labeling has changed over time' gives a clear situational trigger for when to reach for history rather than the current label. No explicit exclusions or named alternatives, but the context is unambiguous.

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