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

No annotations are provided, so the description carries the full burden. It usefully discloses the directory is curated ('approved') and enumerates the returned fields, but says nothing about pagination, default/maximum result counts, sorting, or whether results are ranked by relevance.

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?

Two sentences, front-loaded with the verb and resource, with the field enumeration serving a real purpose since no output schema exists. Nothing is redundant.

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?

The return-shape sentence compensates well for the missing output schema, and the curated-directory framing sets expectations. The remaining gap is parameter behavior (limit, matching rules), but for a read-only keyword search the description is largely sufficient to call it correctly.

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%, so the description must carry parameter meaning, and it only partially does. It maps 'keyword' to q and 'capability' to capability but never explains matching semantics (exact vs substring, which fields q searches), and the 'limit' parameter is not mentioned at all.

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 ('Search the StableDomains.net agent directory') and scopes it ('approved AI agents and MCP servers'). It does not explicitly distinguish itself from the sibling get_agent, so an agent must infer that 'search' is for discovery and 'get' is for lookup by identifier.

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?

Mentions 'by keyword or capability', which implies the two search modes, but gives no explicit when-to-use guidance or exclusions. It never names get_agent or list_my_agent as the alternative for retrieving a single known agent, leaving that routing to inference.

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