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

Annotations already declare a read-only, non-destructive, closed-world operation, so the safety bar is low. The description goes further by disclosing cost scope (state fees only, excludes registered-agent/service fees and revenue-based taxes) and return limitations (figures only, no source URLs) — valuable context beyond the 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?

Four tight sentences, all front-loaded: what it ranks, when to use it, what it covers/excludes, and what it returns. No filler or 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?

No output schema exists, but the description compensates by stating what is returned (figures only) and what is omitted (source URLs), plus geographic coverage (all 50 states + DC). An agent has everything needed to call and interpret results.

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 three parameters are already documented, including the enum meaning and the default. The description's parenthetical on first-year total (formation plus one recurring period) largely repeats the schema, adding only marginal value. 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 ('Ranks US states by LLC cost') and enumerates the three ranking bases (formation, recurring, first-year total). It is immediately distinguishable from get_llc_fees, which it explicitly contrasts as the source-URL tool.

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 trigger conditions ('Use when the user asks which state is cheapest to form or maintain an LLC in, or wants LLC costs compared across specific states') and names the alternative tool to use when official sources are needed. Nothing is left to inference.

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