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

Annotations already declare readOnlyHint/openWorldHint=false, so safety is covered, but the description adds meaningful beyond-schema behavior: the result is deliberately non-prescriptive and includes a required disclaimer that must be presented neutrally to the user. It doesn't discuss error cases or limits, but for a static comparison tool the added output-handling guidance is substantive.

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 is returned and the two topic modes; every sentence carries information (scope, disclaimer, neutrality, triggers). Dense but not padded; the parenthetical enumerations are long yet purposeful.

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 return-value burden and does so — result content, the required disclaimer, and the neutral-presentation requirement are all stated, along with when to call it and what each parameter controls.

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 already 100%, so baseline is 3, but the description adds intent-level meaning: it explains that 'homeState' lets the comparison include the user's home-state costs 'which usually matter most' — beyond the schema's plainer wording.

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 precise verb+resource ('returns fixed, factual tradeoffs') and enumerates exactly what each topic value returns (home state vs Wyoming/Delaware/Nevada, foreign-qualification cost; LLC vs S-corp election vs C-corp). An agent can distinguish this from compare_llc_costs without opening either schema.

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?

Explicitly names the triggering user intents: 'which state to form in, whether to form out of state, or which entity type suits their business.' It gives clear use conditions but names no exclusions or sibling alternatives (e.g., when to use compare_llc_costs instead).

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