List Known Trace IDs

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds meaningful behavioral context: the buffer is in-memory and the trace IDs are ordered most-recently seen first, which goes beyond what annotations provide.

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 well-structured into purpose, use-case, Args, and Returns, with no filler. The core purpose is front-loaded in the first sentence, and every line adds useful information.

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?

There is no output schema, so the description correctly supplies the return shape: 'a list of trace ID strings, most-recently seen first'. It also covers both optional parameters and gives a clear usage workflow, so nothing needed to invoke the tool correctly 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?

Schema description coverage is 100%, so both limit and service_name are already fully documented in the input schema. The description essentially repeats the schema information without adding new parameter-level meaning beyond the output ordering.

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 explicitly states 'List all trace/request IDs currently in the in-memory buffer', giving a specific verb, resource, and scope. It also frames the tool as a browsing step before investigating with search_by_trace_id, which distinguishes it from the lookup sibling.

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?

It gives an explicit usage condition: 'Useful when you don't already know a trace ID'. It names search_by_trace_id as the follow-up, clearly explaining where this tool fits in the investigation workflow.

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