Wordsmith text for unsafe attributes

In this commit, we improve some verbiage.

Author: traviscross

src/abi.md

@@ -66,18 +66,17 @@ item's name.
 Additionally, the item will be publicly exported from the produced library or
 object file, similar to the [`used` attribute](#the-used-attribute).
 
-This attribute is unsafe as an unmangled symbol may collide with another
-symbol with the same name (or a well-known symbol), leading to undefined behavior.
+This attribute is unsafe as an unmangled symbol may collide with another symbol
+with the same name (or with a well-known symbol), leading to undefined behavior.
 
 ## The `link_section` attribute
 
 The *`link_section` attribute* specifies the section of the object file that a
 [function] or [static]'s content will be placed into. It uses the
 [_MetaNameValueStr_] syntax to specify the section name.
 
-This attribute is unsafe as using `link_section` allows users to place data
-and code into sections of memory not expecting them, such as mutable data
-into read-only areas.
+This attribute is unsafe as it allows users to place data and code into sections
+of memory not expecting them, such as mutable data into read-only areas.
 
 <!-- no_run: don't link. The format of the section name is platform-specific. -->
 ```rust,no_run
@@ -93,7 +92,8 @@ exported on a [function] or [static]. It uses the [_MetaNameValueStr_] syntax
 to specify the symbol name.
 
 This attribute is unsafe as a symbol with a custom name may collide with another
-symbol with the same name (or a well-known symbol), leading to undefined behavior.
+symbol with the same name (or with a well-known symbol), leading to undefined
+behavior.
 
 ```rust
 #[export_name = "exported_symbol_name"]

src/attributes.md

@@ -33,9 +33,10 @@ Attributes other than macro attributes also allow the input to be an equals
 sign (`=`) followed by an expression. See the [meta item
 syntax](#meta-item-attribute-syntax) below for more details.
 
-An attribute may be considered unsafe. Unsafe attributes must *satisfy* extra
-safety conditions that cannot be checked by the compiler, and are specified
-as the attribute wrapped in `unsafe(...)`, for instance, `#[unsafe(no_mangle)]`.
+An attribute may be unsafe to apply. To avoid undefined behavior when using
+these attributes, certain obligations that cannot be checked by the compiler
+must be met.  To assert these have been, the attribute is wrapped in
+`unsafe(..)`, e.g. `#[unsafe(no_mangle)]`.
 
 The following attributes are unsafe: