marketplace_subscribe

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

The description discloses important behavioral traits: the filter persists locally (MVP stage) and will later be wired to the relay fan-out. This goes beyond the bare schema, but with no annotations, it still omits details like whether subscriptions overwrite existing ones, authentication needs, or side effects on repeated calls.

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 is two sentences long, front-loaded with the core purpose, and every sentence adds value—the MVP context is essential for setting expectations. No wasted words.

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?

While the description clearly states the purpose and gives an MVP note, it lacks any parameter semantics and doesn't explain how to construct the filter or what outcome to expect beyond persistence. Given no annotations and no schema descriptions, this is undercomplete for reliable use.

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% and the description provides no explanation of the 'kind', 'tags', or 'domain' parameters. The agent is left to infer their meaning from parameter names alone, which is insufficient for correct invocation.

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 begins with a clear, specific action: 'Register a subscription filter.' It not only identifies the verb and resource but also distinguishes it from siblings by mentioning its relationship to marketplace_pull, which clarifies its role in the marketplace workflow.

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?

It provides clear context by stating the filter is 'honored by marketplace_pull' and explains the current MVP limitation versus production wiring. This implies when the tool is useful, and while it doesn't explicitly exclude alternatives, the context is sufficient for an agent to understand its place among siblings.

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