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

No annotations are provided, so the description carries the disclosure burden. It adds useful behavioral context like the registry sources and 'security-first scored' behavior. However, it does not state the read-only nature, result format, pagination, or sorting behavior, though search semantics imply a non-destructive operation.

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?

A single, front-loaded sentence with no filler. Every element adds value: the resource, the registry, the scale, the sources, and the scoring behavior.

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?

For a low-complexity search tool with two optional parameters and no output schema, the description is largely sufficient to select and invoke the tool. It covers the registry and scope, though it omits the result shape and any search result limits or ordering expectations.

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 documents both parameters. The description does not add parameter-level detail beyond the schema, but the parameters are simple and self-evident, so the baseline of 3 is appropriate.

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 uses a specific verb+resource pair: 'Search the MarketNow registry of indexed MCP servers.' It adds concrete scope (69k+ across GitHub, npm, PyPI) and a distinctive trait (security-first scored), making it clearly distinguishable from the sibling verification, submission, and check tools.

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?

The description clearly implies this is the registry search entry point, and all sibling tools are non-search operations (domain checks, revocation, fingerprinting, submission, verification). It gives clear context for when to use it, though it does not explicitly name alternatives or exclusion conditions.

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