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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds behavioral context beyond that: the full set of content sections returned and the audience=pets fork to a cat/dog page, which shapes expectations about output. It stops short of noting rate limits or pagination, but for a read-only info lookup that is minor.

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, then usage routing, then the pets conditional. The long section enumeration is slightly heavy but earns its place by telling the agent what content is available. No filler sentences.

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-value detail is not required, and the description still previews the section set. Both parameters are addressed and the sibling routing is spelled out, making the definition complete for a 2-parameter lookup.

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 the baseline is 3, but the description adds meaning by tying audience=pets to the cat and dog page and by noting slug comes from the pet-medications listing in that case. This is more than the schema restates.

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 ('Get a drug's GoodRx information page') and enumerates the sections returned, so the agent knows exactly what content this yields. It explicitly distinguishes itself from goodrx_drug_prices, which is the key sibling ambiguity.

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?

Gives explicit when-to-use routing: 'Use for medication facts rather than prices (goodrx_drug_prices)' and a conditional for the pets audience pointing to goodrx_pet_medications. The agent has both the alternative and the selecting condition.

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