Add or update nodes

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

With only minimal annotations, the description discloses a great deal: idempotency, consent-gate locking, warning-on-early-child behavior, source inheritance, generated parent-child lines in outline mode, and strict verbatim-authoring rules. These are behavioral facts an agent could not infer from the annotations or schema.

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 dense but not bloated; every sentence adds operational value. It front-loads the core action, then organizes field semantics and mode-specific rules in a readable structure. Formatting like line breaks and bold emphasis for the critical outline-mode exception improves scannability.

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 tool with a nearly empty schema and no output schema, this description is unusually complete: it defines node shape, required-ish fields, mode-dependent behavior, prerequisites, and content constraints. An agent can select and invoke it correctly with minimal additional inference.

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 0%, so the description carries the full burden for parameters. It compensates thoroughly by specifying each node field, optionality markers, `prov` values, the `sources` inheritance rule, `parent` constraints, and column behavior. The only top-level parameter not explicitly glossed is `timeline_id`, but its meaning is clear from the tool name and context.

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 opening sentence states a specific verb and resource: 'Batch-add/update timeline nodes (idempotent upsert by id).' The field list and node-specific rules make clear this is for authoring/modifying timeline nodes, not for connections, entities, axes, or deletion. The scope is unambiguous even without naming siblings.

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 gives strong context: it is an upsert, locked until consent is open, and includes mode-specific guidance (e.g., outline mode ignores `col`, linear mode expects column alternation). It does not explicitly state when to use a sibling like delete_nodes or add_connections instead, so it stops short of a perfect 5.

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