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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely useful operational context: the list is hand-checked, each row carries submit URL, Ahrefs DR, account/badge requirements, review wait and notes, and terms change often enough that the agent should warn the user.

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?

Four sentences, front-loaded with purpose, then result contents, then intended use, then a freshness caveat. Every sentence carries information, though the result-field enumeration borders on overlapping with the 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?

With an output schema present the description need not explain return values, yet it helpfully characterizes the rows; annotations cover safety. Usage intent and the data-freshness caveat round it out. Only minor gaps remain, such as ordering/pagination beyond the schema's 'list order' note.

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%, with each of the six filters documented in the schema itself (kind enums, min_dr semantics including the exclusion of unchecked ratings, search prefix matching, no_account, no_required_badge). The description adds no parameter-level detail, so the baseline 3 applies.

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 and resource: searching StarTap's hand-checked list of 100+ startup directories, launch platforms and web directories with a free listing path. The scope and the nature of the dataset are unambiguous, and it enumerates what each result contains.

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 explicit use cases — planning where to submit or launch a product, or finding first backlinks — plus a caution to tell the user to read each submit page. No alternatives exist to differentiate against (no siblings), and there are no exclusion conditions, so a 4 rather than a 5.

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