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

Goes beyond the annotations by spelling out the practical consequence of non-idempotency — 'Each call creates a new link; retries can duplicate links' — which an agent cannot infer from idempotentHint=false alone. It also discloses the authenticated account scoping and the returned fields (link ID, from, to, type, weight), which matters since no output schema exists.

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 action, then preconditions, return value, duplicate caveat and scope limits in a tight sequence with no filler. The final sentence is a slightly long exclusion list but each clause rules out a plausible agent misread.

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 four-parameter mutation tool with no output schema, the description covers what is created, required ownership, ID source, return payload, duplicate risk and out-of-scope actions. Nothing an agent needs in order to call it safely 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 description coverage is 100%, so the direction semantics, the m12/core ID warning and the 0–1 weight convention are already documented in the schema. The description reinforces directionality ('directed relationship') and lists the allowed types, but adds no syntax or format detail beyond the schema. Baseline 3 applies.

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 and resource ('Create a directed relationship between two existing memories') and enumerates the four relationship types, so the agent knows exactly what is produced. It also implicitly separates itself from read-only siblings like 'graph' and 'recall' by framing the tool as link creation.

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 clear preconditions ('Use numeric memory IDs returned by remember or recall; both memories must belong to this account') and explicit scope exclusions (no assistant accounts, no conversation import, no cross-user links). It never names a sibling tool as the alternative for viewing the graph, so it stops short of full routing guidance.

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