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

With no annotations, the description carries the full behavioral burden, and it does disclose the result categorization (sellable, restricted, not ours to sell, taken, not checked), which tells the agent the output is a set of names with defensibility states. It says nothing about cost, rate limits, whether search registers or reserves anything, or how the states are determined; those gaps keep this at a minimum-viable 3 for an unannotated tool.

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 short sentences, front-loaded with the purpose and followed by the return semantics and the input rule. Nothing is padded, though 'each with the state we can defend' is slightly loose phrasing for what is really a status enumeration.

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?

An output schema exists, so return values need not be spelled out, yet the description helpfully summarizes the possible states. For a single-parameter read-style lookup, the purpose, input rule, and result shape are all covered; only operational details (cost, limits, any side effects) are absent.

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 baseline is 3, and the description adds a constraint the schema does not state: the input must be a concept rather than a domain string. That negative guidance materially reduces the risk of calling the tool with the wrong value type, pushing it slightly above baseline.

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 states a concrete verb and resource: find domain names for an idea, returning candidates across every ending with a defensibility state. That is far more specific than the bare name 'search', and the line 'Pass the concept, not a domain' implicitly separates it from domain-taking siblings like audit_domain or check_live. It does not, however, explicitly distinguish itself from suggest_names or scan_namespace, which are plausible confusions.

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?

'Pass the concept, not a domain' gives a genuine input-selection cue that steers the agent away from the domain-checking siblings. There is no explicit when-to-use/when-not statement, no named alternative, and no prerequisites (auth, cost, whether it registers anything) are mentioned.

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