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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds non-obvious behavior: stopped trackings remain listed for 30 days, the operation costs 0 credits, and it is gated to paid plans only. Since there is no output schema, spelling out the returned fields (hot-lane pickup, lane last/next read, allowance totals) further enriches the behavioral picture.

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 uses clear caps-prefixed sections (USE WHEN, COST) and front-loads the core purpose, and every sentence carries information. The opening sentence is long and packs many return fields into one clause, which slightly hurts scannability.

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 read-only listing tool the description covers purpose, usage triggers, retention, cost, plan gating, and even the shape of returned data, so no output schema is needed. Everything an agent needs to select and call the tool correctly is present.

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 limit, offset, status, country, and events_for are all documented in the schema itself. The description adds no extra syntax or semantics for these parameters beyond what the schema provides, so the baseline 3 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?

The description opens with a specific verb+resource ('LIST the products this API key tracks') and immediately distinguishes itself from the sibling track_product by framing it as the resource that track_product populates. It also enumerates the returned fields, so the agent knows exactly what the tool surfaces.

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 'USE WHEN' clause gives concrete triggers (what is being tracked, whether a tracking is live, allowance remaining) and routes the stop-one case to the sibling action (id goes to DELETE /v1/track/{id}), which is explicit when-to-use guidance and an alternative path.

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