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

Annotations already cover the safety profile (readOnly, non-destructive), yet the description adds substantial behavioral context: filters are ANDed, results default-sort by followerCount, data completeness and a freshness date (22 Sep 2026), that some shops lack a username, and which fields are indexed for efficient scanning. It even discloses the response envelope despite there being no output schema.

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 and defaults, then proceeds through per-parameter guidance and the return shape without filler. It is dense and runs long for a description, but each sentence carries distinct operational information rather than restating the schema.

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 22-parameter, zero-required search tool with no output schema, the description covers the missing pieces: filter combination semantics, default sort, data currency, null handling for username, and the { data, total, page, limit } return shape plus the Shopee url per row. An agent has everything needed to build a valid query.

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 only 68% schema coverage, the description compensates with real semantics: registrationNumber interpretation varies by country (Indonesia NIB, Thailand company registration), street/city/district are substrings, city carries prefixes like 'KOTA JAKARTA UTARA', province is uppercase, and sortBy accepts any ShopeeShop column. This explains how to format values in ways the schema alone does not.

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 ('Search Shopee shops') and immediately states scope ('Shops are complete'), which distinguishes it from the singular Shopee_get_shop and from Shopee_search_products. Defaults and filter-combination behavior are stated up front.

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 actionable selection guidance for parameters ('Use registrationNumber for a legal id... Use username for an exact handle', 'set minFollowers or minRating when scanning a market'), which tells the agent how to route a given lookup. It never names a sibling tool or states when not to use this one, so it stops short of the explicit alternative-routing that earns a 5.

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