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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered and the description correctly focuses on behavior. It adds real context the annotations cannot: the data is published monthly, fees are included in the quoted cash price, and — crucially — when fewer than three sellers publish, the response shape changes to a seller list rather than a fair price. That conditional output behavior is the kind of disclosure an agent would otherwise only learn by calling.

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?

A single dense sentence that front-loads the core concept ('The GLP Chart fair cash price, published monthly') before the scope enumeration and the fallback rule. The parenthetical drug list is long but earns its place by defining coverage; otherwise there is no redundancy.

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?

With no output schema, the description carries the burden of explaining returns, and it does so: median all-in cash price, cheapest and highest verified sellers, and the degraded case under three sellers. Minor ambiguity remains about whether monthly publication means a single latest value or a history, and units/currency are never stated, which matters for an open-world pricing 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 description coverage is 100% and the schema already documents both optional parameters, including the exact drug/form/molecule strings. The description mirrors that same granularity (drug, form, dose) rather than adding new meaning such as matching behavior, case sensitivity, or how multi-form drugs resolve. Baseline 3 is correct.

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 states a specific resource with unusual precision: the monthly fair cash price per GLP-1 drug, form and dose, defined as the middle seller's all-in cash price plus the cheapest and highest verified sellers. It never names a sibling (cheapest, get_price) explicitly, but the enumerated scope makes it distinguishable from a generic price lookup. The only gap is that it describes the data rather than using a retrieval verb upfront.

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?

There is no explicit when-to-use or when-not-to-use guidance and no routing to alternatives such as cheapest or get_price. The monthly reference framing and the note about what happens when fewer than three sellers publish imply a 'use this for the benchmark value' role, but the agent has to infer it.

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