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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description usefully adds that the fee is informational and bundled into the flat price rather than charged separately, plus that it is stateless. Solid extra context beyond structured fields.

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 short, front-loaded clauses that lead with the return value and stay free of filler. Terse fragments are efficient, though slightly clipped in style.

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 an output schema covering return values and annotations covering safety, the description only needs to add scope and usage, which it does well. The gap is the undocumented `state` input, which drags it below a 5.

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?

The single `state` parameter has 0% schema description coverage, so the description carries the burden but only alludes to 'state formation filing fee'. It never states the expected format (two-letter code) or how the state selects the fee, leaving the parameter under-specified.

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?

Specific verb+resource: 'returns the state formation filing fee (table amount and formatted string)'. Clarifies its role versus charging tools ('Nothing charges it separately; it is shown as part of what the flat price covers') but does not name any sibling explicitly.

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 clear usage context — 'Used by the certificate step' and 'Stateless lookup — no formation context required' — telling the agent when it applies and what prerequisites are avoided. No explicit alternatives or when-not-to-use guidance, 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.