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

Annotations include readOnlyHint=true, so no need to restate safety. The description adds value by clarifying exactly what 'cost' means (one-time formation, recurring, combined first-year), which is not obvious from the tool name alone. No contradictions with 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?

The description is two sentences, front-loaded with the core action ('Rank states'), and every clause contributes meaning. No fluff or repetition of schema details.

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?

For a simple read-only comparison tool with 100% schema coverage and no output schema, the description covers the essential use case, what it compares, and how to use it. It could mention the output format (e.g., a ranked list) but 'Rank states' implies that. Overall, it is complete enough for the tool's complexity.

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 the schema fully documents all three parameters. The description does not add additional parameter-level semantics beyond what is already in the schema; it only hints at the sort criteria conceptually. Baseline 3 is appropriate.

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 clearly states the tool's function: 'Rank states by what an LLC actually costs.' It specifies the resource (LLC costs across states) and the specific comparisons made (formation fee, recurring cost, first-year total), distinguishing it from siblings like get_llc_fees or compare_formation_options.

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?

The description explicitly provides usage context: 'Use this for cheapest state to form an LLC style questions rather than guessing.' This gives clear guidance on when to use the tool, though it does not mention alternative sibling tools or explicit exclusions beyond 'rather than guessing.'

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