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

With no annotations, the description carries the full burden and does disclose useful behavior: the exact row fields returned (submit_url, free_or_paid, link_type, review_time, etc.), the meaning of blanks ('not verified'), and the dataset license. It omits read-only/pagination/permission details, but 'List' plus the disclosed shape makes the read-only nature clear.

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?

Three front-loaded sentences with zero filler: purpose first, return shape second, procedural caveat last. The field enumeration and the blank-verification note both earn their place because there is no output schema.

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 read-only listing tool with no output schema and no annotations, the description supplies the return shape, data provenance, and a follow-up step, which is most of what an agent needs. The remaining gap is filter semantics for three undocumented parameters.

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 only 40% (free and dofollow documented; query, requires_account, ai_agent_friendly bare), and the description says nothing about any of the five parameters. It does not compensate for the gap, so an agent must guess at query syntax and what ai_agent_friendly filters on.

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 verb+resource ('List directories and listing sites where an indie product can be submitted') and names the data source, so it is clearly distinguishable from siblings like list_categories and search_projects.

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?

Gives a concrete workflow cue — 'Run run_launch_check on the product site before submitting' — which routes the agent to a sibling at the right moment. It does not, however, state when not to use this tool or how the filters relate to a given use case.

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