analyze_reachability

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

With no annotations, the description carries the full behavioral burden. It discloses the return shape (reachable_nodes, distances, target_reachability), which signals a pure read-only analysis, but says nothing about graph-size limits, performance, or whether the diagram must be loaded first.

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?

Front-loaded with the core purpose, then structured Args/Returns sections with no filler. The docstring scaffolding (Args:/Returns:) is boilerplate but not wasteful.

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?

All three parameters are documented and an output schema also exists, so return values are covered. The main gap is the absence of any routing context relative to the many sibling tools, which is not strictly required for correct invocation.

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 must compensate, and it does: diagram_id, source, and targets are each given meaning, including that targets is optional and used for specific-node checks. It stops short of explaining format/syntax, but substantially closes the gap.

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 first line gives a specific verb+resource ('Analyze reachability from source node') and the second clarifies the computation (reachable nodes and distances). It's clearly a graph-analysis operation, though it doesn't explicitly distinguish itself from the closest sibling, navigate_breadth_first.

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?

There is no when-to-use guidance, no prerequisites, and no mention of when to prefer this over navigate_breadth_first, navigate_guided, or explore_reasoning_space. The description only defines what the tool computes, leaving tool selection to inference.

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