Text-Toolkit

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the basic operation but doesn't describe what happens with multiple matches (e.g., returns all matches, first match only), error handling for invalid patterns, performance implications, or output format. For a regex tool with 3 parameters and no annotation coverage, this leaves significant behavioral gaps.

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 extremely concise at just 5 words ('Extract matches using a regex pattern'), with zero wasted words. It's front-loaded with the core purpose. Every word earns its place, making it efficient despite its simplicity.

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?

Given the complexity of regex operations, 3 parameters with 0% schema coverage, no annotations, and no output schema, the description is incomplete. It doesn't explain what the tool returns (e.g., array of matches, match objects), how it handles edge cases, or provide examples. For a tool with this level of potential complexity, the description is inadequate.

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 compensate for undocumented parameters. It mentions 'regex pattern' which relates to the 'pattern' parameter, but doesn't explain the 'text' parameter (input string to search) or 'flags' parameter (regex flags like 'i' for case-insensitive). The description adds minimal value beyond the schema, failing to adequately cover the 3 parameters.

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 'Extract matches using a regex pattern' clearly states the verb ('extract') and resource ('matches'), specifying it's a regex-based extraction operation. It distinguishes from siblings like regex_replace, regex_split, and regex_test by focusing on extraction rather than replacement, splitting, or testing. However, it doesn't explicitly differentiate from non-regex siblings that might also extract text.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention when regex extraction is preferable over other extraction methods (like string_substring), nor does it clarify when to choose between regex_extract, regex_replace, regex_split, or regex_test. No context about use cases or exclusions is provided.

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