get_token_breakdown

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

Annotations already communicate read-only, idempotent, and non-destructive behavior. The description adds useful behavioral details beyond the annotations: results are in turn order, and an unknown or non-owned session returns an empty list. It does not specify units for latency, but the annotation coverage lowers the burden.

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 compact and well-structured: a definitional first sentence, a usage-routing second sentence, and a parameter/edge-case note. Every sentence earns its place without redundancy.

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?

For a single-parameter read-only operation, the description covers purpose, expected output shape, turn ordering, token and latency aspects, parameter provenance, and the empty-list edge case. No output schema exists, but the description provides enough conceptual shape to invoke the tool 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 input schema provides no description for session_id, so the description compensates by explaining that session_id comes from get_recent_sessions or record_session. This gives an agent the source and provenance of the parameter, which is meaningful given the 0% schema description coverage.

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 states a specific verb and resource: it provides per-turn input/output token and latency breakdown for one session, in turn order. It also explicitly distinguishes itself from get_session_metrics, so an agent can tell when this tool applies.

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 gives direct usage context: use this tool to see how token usage grew turn-by-turn within a session, and use get_session_metrics for session totals. This explicit routing to a sibling tool makes the selection criteria clear.

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