reachable_from

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

With no annotations, the description must carry full burden. It only states 'transitively reachable' without detailing behavior like cycle handling, depth limits, or what happens if the source node is missing. This is insufficient for an agent to understand side effects or constraints.

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 concise sentence, but it omits critical information about parameters and behavior. Conciseness is not an excuse for incompleteness.

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?

Despite having an output schema (not shown), the description is too minimal for a graph traversal tool. It does not explain the meaning of 'transitively reachable' in the context of this server's graph model, nor does it clarify how results are structured.

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 input schema has two parameters (name, session_id) with 0% description coverage. The description adds no explanation about these parameters, leaving the agent guessing what 'name' refers to (node name? graph name?) and what 'session_id' does.

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 'Return nodes transitively reachable from the source node' clearly states the verb (return) and resource (nodes with transitive reachability), and it distinguishes this tool from siblings like 'paths_between' or 'ancestors_of' by specifying the 'transitive' nature.

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 no guidance on when to use this tool versus alternatives (e.g., 'paths_between' or 'subgraph'), nor does it mention any prerequisites or limitations.

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