Trace TNL usage

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

Annotations indicate not readonly (readOnlyHint: false) which aligns with the record mode. The description adds context beyond annotations: it clarifies dual behavior (record/read) and that server overwrites timestamps on event. This provides useful behavioral details not captured by structured fields.

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?

Two clear, concise sentences. Front-loaded with the dual nature of the tool, then unambiguous usage rule. Every sentence provides value.

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?

Given the tool's complexity (dual mode, 2 parameters, no output schema), the description completely specifies how to use each mode. No additional information is needed for an agent to correctly invoke it.

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 coverage is 100%, so schema already describes both parameters. The description adds minimal extra meaning beyond what the schema provides, like noting that the server overwrites timestamps. Baseline 3 is appropriate since schema does the heavy lifting.

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 specific verbs 'Record or read session events' and clearly identifies the resource 'TNL usage'. It distinguishes read vs write modes, and the sibling tools (e.g., approve_tnl_diff, retrieve_tnl) are clearly different in purpose.

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?

Description explicitly says when to pass event (to record) and when to omit it (to read), guiding the agent on mode selection. However, no guidance on when to use this tool versus the other sibling tools is given, as the tool's purpose is quite distinct.

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