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

Annotations already declare readOnly/openWorld=false/non-destructive, so the safety profile is covered. The description adds real value beyond them: it enumerates what is returned (fees, cadence, processing time, gotchas, labeled official source URLs) and discloses data provenance/freshness ("dataset verified 2026").

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 the payoff (what the tool returns) and each sentence earns its place, including the usage trigger. The trailing "Covers all 50 states + DC" mildly duplicates the state parameter's own description.

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 must carry the return-value burden, and it does: it names every field category returned plus the source-URL list and dataset vintage. For a single-parameter read-only lookup this is complete enough to invoke confidently.

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% and the single `state` parameter is documented with both accepted formats ("WY" or "Wyoming"). The description adds no syntax or format detail beyond the schema, 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 (get/returns) and resource (one state's LLC formation fee, annual-report cost and cadence, processing time, gotchas, source URLs). The explicit "one US state's" scoping cleanly separates it from the multi-state sibling compare_llc_costs without the agent needing to open 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?

Gives a clear triggering condition: "Use when the user asks what it costs to form or keep an LLC in a specific state." It does not name alternatives (e.g. compare_llc_costs for multi-state or preview_order for purchasing) or state when not to use it, so it stops short of full routing guidance.

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