what_calls

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

No annotations are provided, so the description carries the full behavioral burden, yet it only discloses edge direction. It says nothing about whether results are direct calls only or transitive, how the `fn` identifier is resolved (name vs. qualified name vs. symbol ID), or what happens when the symbol is unknown or ambiguous.

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?

A single front-loaded sentence with no filler; the directional qualifier is placed where it does the most work. It is efficient, though its brevity contributes to the gaps in other dimensions.

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 presence of an output schema relieves the description of explaining return values, but with zero annotations and an entirely undocumented parameter, the definition still leaves the agent without the identifier format or result semantics needed to call it reliably.

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 single parameter `fn` has 0% schema description coverage, so the description must compensate and does not. It never clarifies whether `fn` expects a bare function name, a fully-qualified path, or an entity ID — the one detail an agent most needs to invoke this correctly.

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 specific verb+resource: querying which functions a given `fn` calls, and adds the directional qualifier "正向调用边" (forward call edge), which implicitly separates it from the reverse-direction sibling who_calls. It stops short of naming that sibling, so the differentiation must be inferred rather than read.

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?

Usage is only implied: the parenthetical "forward call edge" hints that this is the forward-direction counterpart to who_calls, but no explicit when-to-use / when-not guidance or alternative is named. An agent must know the sibling set to choose correctly.

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