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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true, destructiveHint=false), so the description only needs to add operational context — and it does: 40 results per page, next_page pagination, zero quota cost, and the POST /gettracklist endpoint. This is meaningful information beyond the annotations.

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?

Three compact sentences, purpose and pagination front-loaded, followed by filters and the quota note; little waste. The listing of returned fields is slightly dense but earns its place since there is no output schema.

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 usefully describes the fields returned, the 40-per-page paging behavior, and the cost profile, which is enough for correct invocation. Missing only explicit routing guidance against the sibling tools that overlap in purpose.

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 the schema already fully documents all nine parameters, including carrier codes, enum values and date formats. The description only restates the filter categories (carrier, state, package status, registration date) without adding syntax or format detail, so 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?

States a specific verb and resource — search tracking numbers registered on this account — and enumerates the returned fields (carrier, status, registration/last-update times, latest event). This clearly separates it from single-number siblings like track17_get_tracking and track17_realtime_lookup, though no sibling is named explicitly.

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 usable context: the filter axes available (number, carrier, tracking state, package status, registration date) and the important cost note that it is free and does not consume quota, which helps an agent pick it over quota-burning alternatives. No explicit when-not or named alternative is given, so it stops short of 5.

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