proj_call_graph

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuine behavioral context beyond that: the traversal is recursive and bounded by a depth limit, and it enumerates what kinds of callees appear (FB instances, functions, methods). It does not mention cost growth or truncation behavior at deep depths.

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 tightly written sentence with the resource and output front-loaded and the depth constraint and use case appended. No filler; the trailing parenthetical is slightly redundant but earns its place by signaling intent.

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 read-only, two-parameter query tool with an output schema already defining the return shape, the description covers what is computed and how deep it goes. The only material gap is the accepted format for `root` and the absence of any alternative-tool routing.

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 0%, so the description carries the burden. It explains the semantics of `depth` (recursion bound) well, but it never clarifies what `root` must be – a POU name, a qualified symbol path, or something else – which is the required parameter. Partial compensation only.

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 names the resource precisely (a POU – program or function block) and the artifact produced (a call graph of invoked FB instances, functions and methods), which is distinct from sibling tools like proj_references or proj_interface. It does not explicitly name a sibling it is contrasted with, so it stops short of a 5.

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 parenthetical 'what runs when this POU runs' implies the use case (static understanding of runtime reachability), but there is no explicit when-to-use statement and no guidance on when proj_references or proj_interface would be the better choice. Usage is inferable rather than stated.

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