trigger_backfill

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

Annotations are all false, so description carries the burden. It discloses that the tool initiates an immediate write operation, progress is reported via SSE, and completion time (seconds to tens of seconds). It does not contradict annotations. The behavior is well-described except for idempotency or effect of repeated calls.

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?

Three sentences, front-loaded with the action, no redundant information. Every sentence adds value (action, use case, progress reporting, time estimate). It is highly concise and well-structured.

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?

The description explains the core capability, use case, and progress mechanism. However, it does not mention the return value or output format (e.g., job ID, success status), which would be helpful given no output schema. For a simple trigger tool, this is a moderate gap.

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 all three parameters (symbol, market, years). The tool description does not add new parameter-specific meaning beyond the schema. It provides context (e.g., '歷史日線') but no syntax or format details, so baseline score of 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?

The description clearly states the tool triggers an immediate historical daily backfill for a specified stock, distinguishing it from scheduled backfill ('不等排程'). It also specifies the use case: when chart history is insufficient. This differentiates it from the sibling tool trigger_batch_backfill, which likely handles batch operations.

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 context for when to use ('適合當圖表顯示歷史資料不足時'), implying it is for on-demand backfill. However, it does not explicitly state when not to use or mention alternatives like the sibling tool trigger_batch_backfill. The guidance is implicit but lacks direct exclusion or comparison.

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