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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so safety is covered. The description adds meaningful context beyond that: it enumerates what is returned, discloses the no-input fallback behavior, and adds the 'Informational, not legal advice' caveat. It does not state any rate limits or authority constraints.

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 core question the tool answers, then the input modes, then the return contents. The sentence listing return fields is long and dense but each element (statute, quote, source, as-of date, federal rule, bottom line) is substantive rather than filler.

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 thoroughly, enumerating jurisdictions, statute, quote, URL, as-of date, federal rule and a cross-border bottom line. Optional-parameter behavior (empty input) is also covered, leaving no obvious gap for an agent to call it correctly.

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 both parameters are already documented, setting a baseline of 3. The description adds the either/or query mode framing ('by state or by the phone numbers on the call') and clarifies that multiple jurisdictions can be supplied at once, which is modest but real added value.

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 and resource ('look up whether a phone call may be recorded with one party's consent or needs every party's consent') with the exact scope (US states, DC, Canadian provinces). It is clearly distinguishable from siblings like list_state_calling_rules and ai_voice_disclosure_rules, which cover different regulatory questions.

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 context for when to use it — checking recording-consent law by state or by the call's phone numbers — and explicitly covers the no-input case ('With no input, returns the lists of all-party, mixed and one-party states'). It does not name a competing sibling tool or state exclusions, so it falls just 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.