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

Annotations already cover readOnly=false, destructive=false, idempotent=true, and openWorld=false, so the description is not the sole source of behavioral information. It adds only 'hosted' and 'privacy-filtered' context, but does not explain what side effect occurs when a new executionId is supplied or how idempotency is enforced. No contradiction with annotations exists.

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 sentence with no filler, so it is brief. However, the phrasing 'Update hosted begin agent execution' is grammatically awkward and under-specified, so brevity comes at the cost of clarity.

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 9-parameter tool with a nested object and no output schema, this description is far too thin. It does not explain when the call happens, what the call returns, or how it relates to other execution/session lifecycle tools, leaving the agent to guess from the schema alone.

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?

With schema description coverage at 0%, the description needed to compensate, but it only vaguely references 'privacy-filtered project metadata'. It does not explain executionId, threadId, trigger, occurredAt, idempotencyKey, agentId, parentExecutionId, or the nested requestMetadata object.

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 says 'Update hosted begin agent execution' but it never states whether this tool begins, records, or modifies an agent execution. The verb 'Update' conflicts with the action implied by the tool name and is not differentiated from lifecycle siblings such as start_agent_session, finalize_agent_execution, or finish_agent_execution.

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 call this tool versus alternatives, no lifecycle context, and no prerequisites or exclusions. The only useful signal, 'privacy-filtered project metadata', suggests what data to pass but not when the operation is appropriate.

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