deepseek_fim

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It does reveal an important distinction: API Key mode uses the native FIM interface, while web version simulates via dialogue. However, it omits other relevant behaviors such as required authentication, rate limits, or the exact output format, leaving room for ambiguity.

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 a single compact sentence that front-loads the core purpose ('Fill-in-the-Middle') and adds only essential context about the two modes. Every word earns its place with no fluff or repetition.

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 a simple FIM tool with fully documented parameters, the description provides adequate context: what it does, how it operates in different modes, and the expected input. It lacks an explicit statement of the return value, but for this tool the output (generated middle code) is easily inferred. The absence of an output schema is partially mitigated by the straightforward nature of the tool.

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?

The schema covers all parameters with descriptions (100% coverage), so the baseline is 3. The description text mentions prefix and suffix but does not add extra meaning beyond the schema, such as parameter constraints, defaults, or interactions.

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's purpose: 'Fill-in-the-Middle 代码补全' (fill-in-the-middle code completion) and explains it generates middle code from a prefix and suffix. This specific verb+resource combination distinguishes it from sibling tools like deepseek_chat and deepseek_reasoner, which are for general conversation or reasoning.

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 implies usage context by naming the specialized FIM functionality, but it does not explicitly compare to alternatives or state when to prefer this over other DeepSeek tools. It does provide some usage-related guidance by mentioning two modes (API Key native FIM vs web version simulated), which helps the agent understand environment-dependent behavior.

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