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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true. The description adds a note about 'privacy-filtered' metadata, which hints at data handling behavior, but it does not disclose side effects, permissions, or the nature of the update beyond the verb. It does not contradict annotations, and the additional context is minimal but nonzero.

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 that gets straight to the point. It is front-loaded with the core action and resource. However, it is so brief that it sacrifices necessary detail for conciseness, which keeps it from a 5.

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?

The tool is complex (7 parameters, nested object, enum, idempotency key) but the description offers no context on parameter semantics, expected use cases, or return behavior. There is no output schema, so the description carries the full burden, and it fails to explain what the tool does beyond a high-level statement. This is far below the minimum needed for an agent to call it correctly.

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?

The schema description coverage is 0% – the description does not mention any of the seven parameters (executionId, activityId, occurredAt, projectIds, category, idempotencyKey, changeMetadata). With no schema documentation and zero parameter context in the description, an agent has no idea what values to provide or how they relate to the operation.

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 uses a clear verb ('Update') and a specific resource ('hosted record agent execution activity'), which distinguishes it from broader siblings like record_activity and activity_write. The phrase 'privacy-filtered project metadata' adds a distinguishing nuance, but the exact meaning of 'record agent execution activity' remains somewhat ambiguous, so it doesn't fully earn a 5.

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 its siblings (e.g., record_activity, begin_agent_execution, finalize_agent_execution). It does not state any exclusions or alternatives, leaving the agent to infer context from the name alone. This is a significant gap.

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