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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the safety and retry profile is covered structurally. The description adds one useful behavioral fact — that only privacy-filtered project metadata is transmitted — but says nothing about what the update affects or what the caller should expect afterward.

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?

A single efficient sentence with no padding. The wording is slightly garbled ("hosted rebuild context graph") but nothing is wasted or buried.

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, the annotations and full schema coverage carry most of the burden, and there is no output schema to explain. However, the description leaves the core ambiguity (rebuild vs. update) unresolved, which is the one thing structured fields cannot supply.

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 all five parameters are documented in the schema itself, including the idempotency key semantics and the bounded "details" object. The description adds no parameter-level meaning beyond that, so the 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 verb ("Update") and a resource ("hosted rebuild context graph"), but the phrasing conflates the action of rebuilding with updating a graph, so it is unclear whether this triggers a rebuild or mutates graph state. It does not distinguish itself from graph siblings such as patch_project_graph, publish_project_graph, or graph_sync.

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 when-to-use or when-not-to-use guidance and no mention of the many graph-related alternatives in the sibling list. An agent cannot infer from the description when this tool is the right choice over patch_project_graph or graph_sync.

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