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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuine value beyond that by stating the response carries an official source URL and a checked date, which tells the agent the answer is citable and freshness-stamped. It is silent on what happens for unsupported jurisdictions or when no rule exists, which is the main residual gap.

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?

Two sentences: trigger conditions first, return payload second. The synonym list is long but each term earns its place as a routing cue for an agent matching user phrasing.

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?

A two-parameter lookup with no output schema, and the description covers both invocation triggers and the shape of the result (rule text, source URL, checked date). Only the negative case — no rule available for a jurisdiction — is left unspecified.

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 enum values plus jurisdiction formats are fully documented in the schema itself. The description only echoes the state/province framing already present there, adding no format or disambiguation detail beyond the schema baseline.

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-plus-resource (retrieve annual/biennial report rules) and enumerates the filing types it covers, so an agent can recognize the request class immediately. It does not explicitly separate itself from the sibling check_filing_deadline, which plausibly covers overlapping due-date territory.

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 opening 'Call this when a user asks about...' gives a clear positive trigger with several user phrasings (annual report, biennial report, statement of information, annual return). No exclusion or alternative is named, so an agent facing a bare 'when is my filing due?' question must guess between this and check_filing_deadline.

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