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

Annotations already declare readOnlyHint=true, so the read-only nature is implied. The description adds the specific promise 'Returns full node details,' which goes beyond the annotation by specifying the output's completeness. It does not contradict annotations and adds useful context about what the caller can expect.

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 short sentences with no filler. The action is front-loaded, and every word contributes value. It is appropriately terse for the tool's simplicity.

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?

With an output schema present (as indicated), the description need not enumerate return fields. For a single-parameter read tool, the description covers the essential information: what to provide (node ID) and what to expect (full node details). No missing critical context 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. However, the sole parameter node_id is self-explanatory and already documented in the schema as a UUID. The phrase 'by its ID' merely restates the parameter's purpose without adding new meaning. Given the trivial nature of the parameter, a score 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 specifies a concrete action ('Read a node') and resource ('by its ID'), clearly distinguishing it from siblings like list_nodes (which lists nodes without an ID) and create_node/update_node. It leaves no ambiguity about what the tool does.

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 statement 'Read a node by its ID' clearly implies the tool is used when you already have a specific node ID. While it does not explicitly contrast with list_nodes (e.g., 'use list_nodes to browse all nodes'), the context is unambiguous enough for an agent to decide. It lacks explicit exclusions but is clear.

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