get_friend_count

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

No annotations are provided, so the description carries full burden. It mentions the date parameter and default behavior but lacks details on permissions needed, rate limits, error conditions, or what the return value looks like (e.g., integer count, JSON structure). This is a significant gap for a tool with no annotation coverage.

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?

The description is two sentences with zero waste: the first states the purpose, and the second provides parameter guidance. It is front-loaded with the core functionality and appropriately sized for a simple tool.

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?

Given the tool's low complexity (one optional parameter) and high schema coverage, the description is adequate but incomplete. It lacks output details (no output schema) and behavioral context (no annotations), which are needed for full understanding. It meets minimum viability but has clear gaps.

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 schema already documents the 'date' parameter fully. The description adds minimal value by restating the format (YYYYMMDD) and default (yesterday), which is already in the schema. Baseline 3 is appropriate as the schema does the heavy lifting.

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?

The description clearly states the specific action ('Get the number') and resource ('LINE OA friends/followers') with precise scope ('on a specific date'). It distinguishes from siblings like 'get_followers' (likely listing individuals) by focusing on count retrieval.

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?

The description provides clear context for when to use it (to obtain follower count on a date) and includes a default behavior (yesterday if omitted). However, it does not explicitly state when not to use it or name alternatives among siblings, such as 'get_account_info' which might include similar data.

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