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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so safety is covered. The description adds real behavioral value beyond that: it explains the onsite/offsite/in-store tag scheme, the rule that offsite must never be treated as a shelf slot, that values are verbatim from the program, and that empty results should halt the agent.

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 short sentences with little filler, but the structure is fragmentary and telegraphic ('Match a package: what one banner's media program says it sells'), which costs clarity. Key scoping information is not front-loaded.

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?

An output schema exists, so return values need not be described, and the annotations cover the safety profile. What remains missing is parameter semantics for a tool with two required inputs, which is the primary contextual gap for a list/retrieval tool in this domain.

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 0%, so the description must carry parameter meaning, but it names no parameters at all. It only implies banner scoping ('one banner's media program'); 'market' and the optional 'decision_id' are entirely unexplained.

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 conveys that it retrieves what a banner's media program sells (packages) and how they're tagged, but the opening verb is 'Match a package' rather than 'list', leaving the actual operation ambiguous. It never distinguishes itself from siblings like quote_package or renew_package that operate on the same package concept.

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?

No when-to-use guidance and no named alternatives against a large sibling set. The only usage-adjacent statement is the empty-result rule ('Empty where no program is listed — the agent stops'), which describes a downstream behavior rather than when to call this tool.

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