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

Annotations already cover read-only/idempotent/non-destructive/open-world, so safety is settled. The description adds substantive behavioral context beyond annotations: what the result set contains (Cap. number, EN/TC titles, in-force status, instrument type) and the data source. Missing only edge behavior like empty-result handling or pagination beyond limit.

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-loads the core purpose, then the limitation, then the chapter-number mode, then the return shape. Dense but every clause earns its place. Minor: return-shape detail could be trimmed since it is not actionable for invocation.

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 two-parameter read-only search with 100% schema coverage, the description supplies the critical caveat (title-only, not full-text), the numeric shorthand path, and the downstream linkage to hk_law_info/hk_law_section. Nothing an agent needs to call it correctly 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% for both parameters, so the schema already documents query formats and the limit range. The description adds value by surfacing the chapter-number exact-match mode and bilingual examples, but does not meaningfully extend beyond schema content. Baseline 3 applies.

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 (Search) and resource (HK Ordinances, subsidiary legislation, instruments) with the exact search dimension (title keyword). Explicitly excludes full-text search and distinguishes its role from siblings hk_law_info/hk_law_section by noting it returns the Cap. number they consume.

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 says what this is (title search) and what it is not (full-text; will not find a chapter by an inside-section phrase), and describes the exact-match fallback (bare chapter number). This tells the agent when this tool is the right choice versus alternatives.

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