diagram_edge

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

Annotations already declare destructiveHint=true and idempotentHint=true; the description reinforces this by disclosing the upsert rule (re-calling with the same endpoints updates the label rather than adding a duplicate edge). It stops short of describing failure behavior, e.g. what happens when the edge or endpoints do not exist, or whether delete requires the label.

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?

Two short sentences with the multi-mode capability front-loaded and the upsert caveat immediately after; no filler. Slightly dense phrasing ('wire ... that wire') but nothing is wasted.

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 mutation tool with no output schema, the description covers the three operations and the key idempotency behavior, and annotations carry the safety profile. Gaps are minor: error conditions and the relationship to diagram_link are not covered.

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 every parameter, including the branch-condition semantics of label and the removal semantics of delete, is already documented in the schema. The description adds no syntax, format, or default details beyond that, so the baseline of 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 concrete verbs (wire, relabel, remove) and the resource (two steps of a diagram), covering all three modes of the tool. It does not distinguish itself from the sibling diagram_link, which sounds like it could do something similar, so an agent cannot fully rule siblings in or out from the description alone.

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?

There is no guidance on when to choose this over diagram_link, diagram_jump, or diagram_node, and no mention of prerequisites (e.g. that the referenced nodes must already exist). Usage is only implied by the verb list; the alternative tools with adjacent-sounding names are never addressed.

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