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

Annotations already declare readOnlyHint=false and idempotentHint=true, so the safety profile is covered; the description goes beyond them by spelling out the idempotency contract (use a unique requestId and reuse it on retry) and the permission model enforced at workspace, project, and account level. It still omits failure behavior (e.g. what happens when the relationship already exists or the item is unauthorized).

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?

Four sentences, front-loaded with purpose and then constraints; each carries information. The sentence about item updates requiring a current version is tangential to a create operation and mildly dilutes focus.

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 no output schema, the description could have said what a successful call returns (e.g. the created relationship identifier) or how duplicates are handled, and it doesn't. Everything else an agent needs to invoke it correctly — operand format source, required permission, idempotency key discipline — is present.

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 only 50% (kind and requestId have no schema descriptions), and the description compensates by naming the allowed kind values and explaining requestId's uniqueness/retry semantics, which the schema only expresses as a bare string with length bounds. The mention of a 'current version' is not tied to any visible parameter, which leaves some ambiguity.

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?

States a specific verb (Add) plus the resource (relationship) and enumerates the three relationship kinds, so an agent immediately knows what will be created. It is easily distinguished from the sibling relationship_delete, and the 'between two authorized workspace items' phrase scopes the operands.

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?

Gives concrete context: write permission on the items is required, and explicitly warns that associations:write is NOT the right permission, plus it routes the agent to get_tasks/get_items/get_workspace when a version is needed. It does not, however, name alternatives (e.g. association_save) or state when not to create a relationship.

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