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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description reinforces that unspecified fields remain unchanged, which is meaningful mutation semantics, but overlaps with the schema's "partial update" note and says nothing about permissions, error behavior on a missing node, or confirmation of the write.

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, front-loaded with the action and resource, and the second sentence delivers the one behavioral rule that matters most for calling it correctly. 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 non-destructive, idempotent mutation whose annotations already cover the safety profile and whose schema fully documents inputs, the description is nearly sufficient. It only leaves open what happens when the target node does not exist, which is a minor gap given there is no output schema to explain returns.

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 is already documented in the schema, including the partial-update nature of `data` and the environment default. The description adds no syntax or format detail beyond that, so 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 ("Update properties of an existing node") and scopes it to a deployed graph project, which cleanly separates it from create_graph_node and delete_graph_node. It does not name a sibling explicitly, but the intent is unambiguous.

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?

"Existing node" implies this is not for creation, and the partial-update sentence tells the agent how to call it, but there is no explicit when-to-use/when-not guidance or routing to alternatives (e.g., bulk_create_graph_nodes or update_graph_schema). Usage is only implied.

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