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

Annotations already declare readOnly, idempotent, non-destructive behavior, so the safety profile is covered. The description adds the pre-execution intent and the graph shape, but says nothing about what a failed validation returns or how validation is scoped (e.g., config-level checks).

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 supporting input documentation. Three compact lines with no filler, though the 'ExecGraphSnapshot:' shorthand is a bit cryptic for an agent that hasn't seen the type elsewhere.

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?

An output schema exists so return values need not be explained. Given annotations covering safety and the description covering purpose, input structure, and construction path, an agent has enough to call it correctly.

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% but the schema is loose (additionalProperties: true, no field definitions). The description compensates by specifying the actual structure - nodes with {id, type, config} and connections with {from, to} - which the schema does not provide.

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?

Specific verb+resource combination: validate a pipeline graph, with the added scope of 'before running'. It clearly separates from generic validation, though it doesn't explicitly name pipeline.validate_node to disambiguate graph-level vs node-level validation.

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?

'before running' establishes clear context for when to call it, and it suggests the input source (catalog.template(id).train or catalog.nodes()). No explicit when-not or alternative routing to validate_node, so it stops short of a 5.

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