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

Annotations already declare readOnly, idempotent and closed-world, so safety is covered. The description still adds real value beyond them by disclosing the shape of what comes back — human-readable labels paired with values to send back — which matters because there is no output schema.

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 short sentences with no filler; the content description comes first and the id prerequisite second. The telegraphic phrasing ("…patch…", "values to send back") is efficient but borders on informal.

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 simple two-parameter read with full schema coverage and no output schema, the description covers purpose, input provenance and the label/value return structure. Only the as_of temporal option and the exact return container shape are left unstated, both minor for this tool.

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%, so both parameters are fully documented in the schema, including the id prefix conventions and the as_of date-range rule. The description's "use the id from a search hit" largely restates the schema's own wording, and it never mentions as_of.

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?

The description names the resource concretely — the forms (tablet, liquid, patch) and strengths a medication comes in — with parenthetical examples that remove ambiguity. It is clearly distinct from siblings like get_packages (packaging) or lookup_ndc, though it does not name those siblings explicitly.

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?

"Use the id from a search hit" gives the key prerequisite and implies the call happens after a search_medications lookup. There is no statement of when not to use it, nor any pointer to the sibling tools (get_drug, get_packages) that cover adjacent data.

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