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

Annotations already declare the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds genuine context beyond annotations: the exact data source methodology (HKEXnews filings whose title contains 'License Agreement' or 'Licensing Agreement'), the full return payload (company, stock code, headline, filing category, date, PDF), and the HKEX-listed coverage boundary. No contradiction with annotations.

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?

Dense but not bloated — four information-rich sentences, each earning its place: scope, sibling differentiation, example use cases, sourcing, return fields, and coverage limits. The core scope is front-loaded. Slightly long, but the complexity of the coverage boundary justifies the length.

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 read-only retrieval tool with no output schema, the description is thorough: it states source, scope, exclusions, alternative tools, and enumerates the return fields, compensating for the missing output schema. The rolling-window limit lives in the since parameter. Minor gaps remain (pagination, rate limits), but 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 description coverage is 100%, so the baseline of 3 applies. The schema already documents limit, query, since, and until with clear semantics (including the rolling-window caveat on since). The description's example queries imply how the query parameter is meant to be used but adds no parameter-level detail beyond the schema.

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 precise verb+resource: 'Biotech/pharma licensing and collaboration deals disclosed by HKEX-listed companies.' Explicitly differentiates from siblings by scope (deals with NO US-listed party, which SEC-filing-based tools cannot see) and gives three concrete example queries. An agent can distinguish it from every sibling without opening the schema.

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?

Names alternatives (china_licensing_deals, pharma_licensing_deals) and explains why they structurally cannot cover these deals. Gives positive examples ('China-to-Japan biotech licensing deals') and a clear exclusion ('a private-to-private deal with no HK, US or A-share party is invisible to every tool in this catalog'). When-to-use and when-not-to-use are both explicit.

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