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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety and retry profile is covered without the description. The description adds 'privacy-filtered project metadata,' which is genuine context about data handling, but says nothing about auth, retention, duplicate handling, or what effect a repeated idempotencyKey has.

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 twelve-word sentence with no filler, which is structurally clean and front-loaded. However, for a seven-parameter mutation tool with a nested object, this brevity reflects under-specification rather than disciplined conciseness.

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?

This is a complex write tool: seven parameters, six required, a nested object, and no output schema. The description does not establish the tool's purpose, when to invoke it, or how it relates to begin_agent_execution/record_activity, leaving significant gaps for an agent to close on its own.

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 only 43%, and the description supplies no parameter meaning at all. The undocumented parameters (category, occurredAt, and the nested changeMetadata fields) are left for the agent to infer, and the description does not compensate for the coverage gap.

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 phrase 'Update hosted record agent execution activity' largely restates the tool name (record_agent_execution_activity), and the verb shifts from 'record' in the name to 'Update' in the description. The only distinguishing detail, 'using privacy-filtered project metadata,' hints at scope but does not explain what the act of recording actually is. It does not differentiate from near-siblings such as record_activity, activity_write, or begin_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 when-to-use guidance, no preconditions, and no named alternatives. Given the presence of begin_agent_execution, finalize_agent_execution, record_activity, and activity_write as siblings, the agent gets no help deciding when this specific call is the right one.

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