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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety and repeatability are covered. The description adds genuine context beyond that: the output is behavior3 JSON and the response shape switches between a list and a single tree depending on whether id is supplied. It does not say what happens for an unknown id or whether the list is paginated.

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 sentences, no filler, with the content inventory first and the mode behavior second. The parenthetical example list is slightly long but earns its place by showing what kinds of trees are available. Nothing is buried or redundant.

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?

For a one-optional-parameter read tool with full annotation coverage and no output schema, this is enough to call correctly: the agent knows both modes, the return format, and that no id is required. Nothing material is missing.

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 coverage is 100% and the single parameter already documents 'Example id from the list; omit to list them'. The description restates this as a list-versus-fetch switch, which clarifies the consequence of omission but duplicates what the schema already says. Baseline 3 is appropriate when the schema does the heavy lifting.

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 gives a concrete verb and resource ('returns that tree as behavior3 JSON') and characterizes the resource content with real examples (enemy patrol, cooldown-gated attacks, robot navigation). It also spells out the dual-mode behavior, listing versus fetching by id. It stops short of naming a sibling like read_guide or list_node_types, so the boundary is inferred rather than stated.

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?

It states the two usage contexts clearly: call with no id to browse available examples, or with an id to fetch one. The framing 'to learn the format from or start with' signals the intended workflow. It offers no explicit exclusion guidance against the similar-sounding read_guide or list_node_types, which is the only gap.

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