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

Annotations only cover read-only/idempotent safety; the description adds real behavioral context beyond them - the provenance differs by set (CACI uses the Judicial Council's own 'Table of New and Revised CACI' front matter, CALCRIM is derived from per-instruction revision-history lines matched to the edition's adoption date). It also discloses the important failure mode that withdrawn/revoked numbers are undatable here and are returned empty with a note, which an agent could otherwise misread as 'nothing changed'.

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 and an example, with the caveats following. It is dense - the derivation sentence and the double parenthetical about CALCRIM require a careful read - but nearly every clause carries information an agent needs to call it correctly.

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 2-parameter keyless read tool with no output schema, this covers what an agent needs: what the result rows represent (instruction numbers), which sets are covered and how, the current-edition-only constraint, and the empty-withdrawn-number behavior. Nothing material is missing.

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%, so both parameters (set enum and optional edition year) are already fully documented in structured form. The description mostly restates that only the current edition is available, which the schema also states, and adds no format or edge-case detail about the edition string itself. 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?

States a specific verb+resource: which CACI/CALCRIM jury instructions are new or revised in a given edition, with a concrete worked example ('what's new in the 2026 CALCRIM edition' -> No. 1808, 3235...). This clearly separates it from ca_ji_search (searching by content), ca_ji_editions (edition metadata), and caci_lookup/calcrim_lookup (single-number detail).

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 names the alternatives and the conditions that select them: ca_ji_editions for archived editions, and caci_lookup/calcrim_lookup to check revocation status when a number is withdrawn. It also states the negative case up front - only the current edition works, and revoked numbers always come back empty.

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