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

Annotations already establish that the tool is read-only, idempotent, and not open-world. The description adds meaningful behavioral detail by listing the case shapes it detects (ALL CAPS, Title Case, First letter, lower) and stating that the output is shaped per match. It does not describe edge cases such as mixed casing or empty strings, so it is not fully transparent.

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 two efficient sentences with no filler. The core behavior is front-loaded, and the Google Docs reference adds useful context without distracting from the operation.

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 two-parameter helper, the description covers the operation and case-shape categories. However, because there is no output schema, it should more explicitly state the return shape and behavior when matches vary or are empty; those gaps matter for an agent interpreting results.

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 the semantic load. It does explain that 'matches' provides the case-shape source for each replacement, which is useful beyond the raw schema types, but it does not clarify array alignment, the 100-item maximum, or how edge-case values affect the output.

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 specific transformation: given matched texts and a replacement, return each replacement shaped to the case pattern of its corresponding match. It clearly distinguishes itself from generic text-cleaning or spreadsheet-formula helpers. It does not explicitly contrast with siblings, but no sibling appears to perform the same case-preserving replacement.

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 Google Docs 'Keep the case of each match' reference implies a usage context, namely reproducing that ReplaceKit/Google Docs behavior. However, it does not explicitly say when to call this tool versus doing case adjustment elsewhere, nor does it state exclusions or prerequisites.

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