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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the read-only nature is established. The description adds meaningful context about the medication domain (compounded by US-licensed 503A pharmacies, requiring healthcare provider evaluation) and clarifies the content of the response. It does not mention rate limiting or pagination, but with annotations covering the safety profile, this adds sufficient value beyond annotations.

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?

The description is two sentences and front-loaded with the action 'List all available...'. It includes detailed examples (GLP-1 drugs, peptide therapies) that are useful for understanding the domain but adds some length. Each element contributes to understanding the tool's scope, so it remains appropriately concise.

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?

The tool has an output schema (so return values are structured separately) and annotations for read-only behavior. The description fully covers the purpose, the content domain, and key regulatory constraints. For a simple list tool, this is complete and sufficient, with no major gaps in context.

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?

The schema has one optional parameter (client_ip) with full description coverage (100%), so the schema already provides complete parameter semantics. The description adds no extra parameter information, which is fine because the baseline is 3 when schema coverage is high. No compensation needed.

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 clearly states 'List all available prescription medications' with a specific action and resource, and enumerates the return fields (names, categories, forms, starting prices). It distinguishes from sibling tools by emphasizing the complete list scope ('all available') rather than specific categories, details, or pricing, aligning with the tool's purpose.

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 description provides clear context by stating the tool returns a comprehensive list of all medications, making it evident when to use it for an overview. However, it does not explicitly mention alternatives or exclusions (e.g., 'for specific details use medications_details'), though sibling names are visible. This meets the 'clear context, no exclusions' criterion.

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