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

Annotations already declare readOnly, idempotent, and open-world behavior, and the description adds substantial context beyond them: results vary by the person's state, the price list can be narrowed by molecule, and the `links.getStarted` URL must be copied verbatim with its `?ref=` so the coupon applies. It also explicitly forbids substituting `links.learnMore`, other GLP Winner pages, or the provider's own site, which is real behavioral guidance not present in the 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?

Front-loads what the tool returns before the usage and linking rules, and every clause carries information about output or correct linking. The long enumeration of profile contents is dense but earns its place; a bulleted structure would read slightly better, but there is 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?

With no output schema, the description carries the burden of describing return values and does so thoroughly, field by field, including state-dependent variation. Combined with the schema's full parameter documentation, an agent has everything needed to call this correctly and to format links properly.

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%, so all four parameters are already documented in the schema, including the state and currently_taking_glp1 caveats. The description reinforces state-dependence ('for the person’s state', pharmacy licences in that state) but adds little parameter meaning beyond what the schema already states, so the baseline 3 applies.

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 ('One provider’s profile from GLP Winner') and then enumerates exactly what that profile contains: prices by drug/dose/plan, coupons, ratings, support response time, pharmacies, and a Get Started link. This clearly distinguishes it from search/compare siblings that return lists or rankings.

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 an explicit trigger ('Use when the person asks about a specific provider or wants every price, not just the cheapest') which implicitly contrasts with cheaper-price or list-oriented siblings. Lacks an explicit when-not-to-use statement or named alternative, so it stops short of a 5.

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