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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds useful behavioral context — the card is 'signed' and the status vocabulary is enumerated (listed · claimed · verified) — but says nothing about caching, auth requirements, or failure modes when a banner slug is unknown.

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 tight sentences with the core purpose front-loaded and the parameter hint appended. No filler, no repetition of the title.

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 shape needn't be explained, and annotations carry the safety profile. However, with a required 'market' parameter undocumented and no routing guidance against list_banner_cards, the agent is left to guess on a required input.

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 0%, so the description must compensate. It does so for 'banner' by listing accepted identifier forms (slug, id or name), which is genuinely useful, but the required 'market' parameter is left completely undocumented in both schema and description.

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 names a specific resource (the signed card of one banner) and its scope (single banner, plus status), which distinguishes it from the plural sibling list_banner_cards. The retrieval verb is only implied by the noun phrase rather than stated, but the singular/plural contrast makes the intent unambiguous.

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?

There is no explicit when-to-use or when-not-to-use guidance. The agent must infer from singular vs. plural that this fetches one card and list_banner_cards fetches many; no prerequisites or alternatives are named.

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