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

Annotations already indicate it is not read-only, not destructive, and idempotent. The description adds that it uses privacy-filtered metadata, which is useful but does not explain the impact on the graph (e.g., whether it fully replaces the graph or merges). No contradiction found.

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 a single, concise sentence with no wasted words. It front-loads the core action and resource. However, it could have been slightly more structured to include context on parameters.

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 an update operation with 5 parameters (2 required) and a nested object, the description is too sparse. It lacks guidance on how the parameters interact, semantics of the update (e.g., whether all metadata is replaced), and any prerequisites. With no output schema, agents are left guessing about return values or errors.

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 0%, so the description must explain the parameters. It mentions 'privacy-filtered project metadata' which may relate to 'details', but does not explain the role of 'projectId', 'sessionId', 'executionId', or 'idempotencyKey' in the update process. Nested object 'details' is also unexplained.

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?

The description states a specific action ('Update'), a resource ('hosted rebuild context graph'), and a qualifier ('using privacy-filtered project metadata'). This makes it distinguishable from siblings like 'get_context_graph' (read) and 'clear_project_graph' (destructive) but does not explicitly name them.

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?

The description provides no guidance on when to use this tool versus alternatives. It does not mention that it is an idempotent update requiring an idempotency key, nor does it contrast with related tools like 'patch_project_graph' or 'publish_project_graph'.

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