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

With no annotations, the description carries the full burden: it discloses that the catalog is public and key-free and lists the returned fields, which is genuine behavioral context. It omits pagination behavior, result ordering, rate limits, and what happens with large result sets — meaningful gaps for an unannotated read tool.

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 compact sentences, front-loaded with the resource and scope, then the filter and field list. No filler, though the parenthetical field enumeration is dense and slightly list-like.

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?

There is no output schema, so the inline field list usefully compensates by describing the return shape. But with no annotations and an undocumented limit parameter, the description leaves pagination and result-size behavior unspecified, which an agent calling a broad market listing would want.

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 67%, so the baseline is 3. The description repeats the schema's own q description ('filters by title/merchant/description') and says nothing about limit or the fields projection, so it adds no meaning beyond the schema.

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 resource (the public cross-merchant market catalog of published checkouts) and enumerates the fields returned, so the agent knows exactly what it retrieves. However, it never distinguishes itself from catalog-adjacent siblings like search_catalog or lookup_products, so the agent must infer the difference.

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 key' signals the unauthenticated/public browsing case and 'every published checkout across merchants' implies a broad browse rather than a targeted lookup, which hints at when to use it. But there is no explicit when-to-use/when-not and no named alternative, so usage is only implied.

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