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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and closed-world scope, so the safety profile is covered. The description adds genuinely new behavioral context: the brief preserves registry methodology/limitations and deliberately excludes legal advice, compliance determinations, and exhaustiveness claims — an important guardrail beyond what annotations convey.

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?

Three short sentences, front-loaded with the core action, then the disclaimer, then the parameter-provenance hint. No filler; each sentence earns its place.

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 single-param read-only build tool with no output schema, the definition covers purpose, input provenance, cardinality, and output caveats. The only residual gap is how the comparison is presented (format/structure of the brief), which is minor given no output schema exists to define it.

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?

With 0% schema description coverage on the single required `slugs` parameter, the description carries the burden and does so: it names the provenance ('stable slugs returned by search_policy_developments') and the cardinality bound (one to twelve records), both of which the bare array<string> schema does not express.

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?

Opens with a specific verb+resource+scope: 'Build a citation-first comparison of one to twelve registry records.' The 'registry records' framing distinguishes it from bill-legislation siblings, though it does not explicitly contrast with the proximate sibling build_legislative_evidence_packet, which is a similar build-style tool.

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?

Explicitly directs the caller to obtain stable slugs from `search_policy_developments`, giving a clear workflow precedent. It sets boundaries on output (no legal advice, no compliance determinations) but stops short of stating when to prefer this over build_legislative_evidence_packet.

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