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

Annotations already cover safety (readOnly, idempotent, non-destructive), but the description adds substantial non-obvious behavior: the required read scope, a 7-day / 20-attempt retention window, the full outcome taxonomy, per-code meanings, and what untrusted_fields signifies. This is exactly the kind of context the annotations cannot carry.

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 scope requirement and the purpose statement are front-loaded before the detail, which is correct. The long fragmented enumeration of rejection/drop codes is dense but largely earns its place because there is no output schema and the agent needs to interpret the returned reason values.

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?

With no output schema, the description fully carries the burden of explaining returns: it lists each attempt's fields (outcome, reason, span_count, bytes, protocol, user_agent, signal) and enumerates the possible outcome/reason values. Nothing an agent needs to call or interpret this tool is missing.

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?

Only one parameter (monitor_id) and the schema already documents it at 100% coverage, including its source (create_monitor or list_monitors). The description adds no additional meaning about the parameter, so the baseline 3 for schema-covered params 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 specific verb and resource (get trace diagnostics) and immediately defines scope: the newest 20 ingest attempts, last_accepted_at, and the newest traced run's summary. An agent can distinguish this from setup siblings like get_trace_setup or get_ping_instructions without opening any schema.

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?

Gives concrete trigger conditions: 'For checking a test span, or telemetry sent with nothing showing.' That tells the agent when this tool is the right pick, but it never names an alternative (e.g. setup instructions) or states when not to use it, so it stops short of the top band.

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