regex_replace

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

With no annotations, the description carries the burden of behavioral disclosure. It mentions support for capture groups in the replacement, which adds useful detail, but it does not disclose default behavior (e.g., global replacement) or mention error handling (e.g., invalid patterns). The schema provides some of this, but the description could be richer.

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 core description is two concise sentences, but the leading '[PRO — 3 trial uses left]' is unrelated to tool behavior and could confuse an AI agent looking for selection criteria. This unnecessary prefix detracts from the otherwise efficient structure.

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 simple string manipulation tool, the description covers purpose and a key feature (capture groups), and the schema fully documents parameters. The output is not described, but for a replace operation it is implicitly the modified string. The missing default-behavior note is slightly incomplete but compensated by the schema.

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 schema fully documents all parameters. The description's mention of capture groups is redundant with the replacement parameter's description. No additional parameter semantics are added beyond the schema.

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 uses a specific verb ('Find and replace') and names the resource ('text') with a clear mechanism ('using a regular expression'). It distinguishes the tool from sibling 'regex_test' by implying this one performs replacement, not just testing.

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 clearly states the tool's use case (find and replace using regex) and gives a context cue (replacement strings with capture groups). However, it does not explicitly mention alternatives or when not to use it, which is acceptable for a well-scoped utility.

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