open_nodes

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

Annotations already provide readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds valuable context that the tool returns not just the requested entities but also all relations connected to them, which is a behavioral trait not evident from the schema alone. No contradiction with annotations.

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?

Two concise, front-loaded sentences with zero wasted words. It states the action, the resource, and the return value efficiently.

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 simple parameter set (one array), strong annotations, and an existing output schema, the description is nearly complete. It does not explicitly clarify when to use this over search_nodes or read_graph, which is a minor gap given the sibling context, but overall it provides sufficient context for a simple retrieval tool.

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 100% (the 'names' parameter is described as 'List of entity names to retrieve'). The description reinforces that 'names' refers to entity names, but it adds no additional syntactic or format details beyond the schema, so a baseline of 3 is appropriate.

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 states a specific verb ('open') and resource ('specific nodes in the knowledge graph'), and further clarifies the return value ('entities and all relations connected to them'). It is clear and distinct from siblings, but it doesn't explicitly differentiate itself from search_nodes or read_graph.

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 implied: use when you know the exact names of nodes to retrieve. However, there is no explicit when-to-use vs alternatives, no exclusions, and no mention of cases where search_nodes or read_graph would be more appropriate.

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