find_available_domains_by_pattern

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context beyond that: every candidate is 'verified live against the registry,' taken names are omitted, and the tool 'does not register domains.' It also notes default TLDs. This is strong supplemental transparency, though it does not discuss timing or potential empty results.

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 dense and front-loaded: it states the core behavior first, then usage guidance, then behavioral caveats. Every sentence earns its place, and there is no repetition of schema content. Despite its length, it remains tightly organized and easy to parse.

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 enumeration tool with four well-documented parameters and rich annotations, the description is complete. It covers what the tool returns (available domains), how results are verified, default scope, exclusions, and safety. The lack of an output schema is acceptable because the description clearly frames the return as a list of available matching domains.

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. The description reinforces meaning by explaining the pattern positions and default TLDs, but it does not add substantive parameter detail beyond what the schema already provides. This is acceptable because the schema fully documents each parameter.

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 opens with a specific verb and resource: 'Enumerate every currently available domain matching a keyword pattern' across selected TLDs. It names the exact pattern types (starts-with, ends-with, contains, or all) and explicitly differentiates itself from siblings by stating what it is not: not for invented brandables and not for inspecting one known domain.

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 gives explicit when-to-use guidance: 'Use this when the user already has a keyword and wants an exhaustive list.' It also provides direct exclusions with named alternatives: 'Do not use to brainstorm creative names (use find_available_domains) or to inspect one known domain (use check_domain).' This leaves no ambiguity about tool selection.

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