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

The description states repeated calls do not create duplicates but update the edge, which implies idempotent behavior. Annotations set idempotentHint=false, directly contradicting this claim. Per the scoring rule, a contradiction caps this dimension at 1.

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 front-loaded with purpose, then behavior, then alternatives. It is concise overall, though the trailing '| EN: object, record, entry...' synonym list is search-oriented noise rather than useful agent guidance.

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 6-parameter mutation with no output schema, the description covers creation, duplicate handling, link-type discovery, and the update alternative. Annotations carry the safety profile, though the idempotency conflict is a notable caveat.

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 baseline is 3. The description references link type and objects but adds no syntax, allowed values, or guidance for scope_id, linkvalue, or linkvalue_free beyond the schema.

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: connect two objects via a link type. Explicitly names the sibling tools onto_link_index and onto_object_update_link, distinguishing creation from link-type lookup and edge update.

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?

Explains when to use this tool (connecting two objects), where to discover available link types (onto_link_index), and which alternative handles existing edges (onto_object_update_link). The when-not case is covered by naming the update tool.

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