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

Annotations already declare readOnlyHint and openWorldHint=false, so safety is covered. The description adds real behavioral context: the result is unpaged ('Not paged') and includes `forms` and `reading` fields that explain every term. It stops short of describing volume or shape of the returned lists.

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?

Very dense and front-loaded: purpose first, then routing, then parameter semantics, then return note. Every clause earns its place, though the telegraphic, comma-spliced style costs a little readability.

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 needn't be re-explained, yet the description still notes the lists, `forms`, and `reading`. Combined with clear param semantics and annotation-covered safety, an agent has what it needs, with only the value formats for `type`/`via` left implicit.

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 carry the load, and it does: `type` narrows every list, `direction` gives one side of relations and needs `type`, `via` scopes relations and enums. It covers all three params meaningfully, though it doesn't state the accepted value format for `type` or `via`.

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?

Names the specific resource (relations declared between types) and enumerates what it covers: references with form/cardinality, ownership, enums, joins, list kinds. It explicitly distinguishes itself from the sibling describe_schema, so an agent can route without opening either schema.

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?

States the use case ('for a diagram or audit') and names the alternative with its selecting condition ('for one type's full schema use describe_schema'). It also flags the dependency that `direction` requires `type`, which is usage guidance beyond the schema.

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