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

Annotations already provide readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context by warning that link type and price may be 'unknown' and should be treated as unverified rather than as free or dofollow. This goes beyond the annotations and helps the agent interpret results correctly.

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 with no fluff. The first sentence front-loads the action and criteria, the second covers the return type and a crucial data-quality caveat. Every sentence earns its place, and the structure is logical.

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 tool with 9 parameters and an existing output schema, the description covers the core purpose and adds a critical caveat about unverified values. It does not mention pagination, sorting, or result count, but these are handled by the schema parameters. The description is sufficiently complete for an agent to invoke the tool correctly, given the rich structured metadata.

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?

The input schema documents all 9 parameters with descriptions and enums, achieving 100% coverage. The description does not add meaning to the parameters themselves; it merely lists some filter criteria already present in the schema. The 'unknown' caveat pertains to result values, not input semantics. Since coverage is high, 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 clearly states the tool filters startup/SaaS/AI directories by multiple criteria (category, DR, link type, price, badge swap) and returns submit URLs. The verb 'Filter' is specific and the resource is explicit. It does not explicitly contrast with sibling tools like find_alternatives or search_listings, but the purpose is unambiguous and not a tautology.

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 offers no guidance on when to use this tool versus alternatives. It does not mention any exclusions or contexts where another tool (e.g., recommend_launch_directories or get_launch_directory) would be more appropriate. The reader is left to infer usage from the filtering semantics alone.

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