nexus_call_graph

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

Annotations already declare the tool as read-only and idempotent, so the safety profile is clear. The description adds no behavioral details beyond the purpose, such as return format, pagination, or any side effects. With annotations covering the safety aspect, a score of 3 is appropriate.

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 extremely concise and front-loaded, using only essential words to convey the tool's function. Every word is meaningful, and there is no redundant information. It is appropriately sized for a tool with a simple purpose.

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 simplicity and the presence of read-only annotations, the description provides a minimal viable explanation. However, it does not describe the output format, nor does it clarify how this differs from closely related sibling tools like nexus_references or nexus_dependency_graph. Additional context would help an agent select the correct tool, but the description is not wholly inadequate.

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 only provides a description for 'symbol' (33% coverage), so the description must clarify 'depth' and 'direction'. The phrase 'depth-N' and 'callers or callees' partially compensates by explaining the role of depth and direction, but it does not mention default values or range constraints, which are only available in the schema. This adds some value but not full compensation.

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 'Callers or callees of a function, depth-N' precisely states the tool's purpose: it returns the callers or callees of a given function up to a specified depth. This distinguishes it from sibling tools like nexus_references or nexus_dependency_graph by focusing specifically on function call relationships with a depth parameter.

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 does not explicitly say when to use this tool versus alternatives such as nexus_references or nexus_dependency_graph. However, the name and phrase 'callers or callees' imply when it is appropriate, and the absence of exclusions or alternative recommendations leaves usage guidance implied rather than explicit.

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