طارد الحشرات وحقيبة الإسعافات الأولية داخل الخيمة.

Because this is a nominal sentence in the present tense. In Modern Standard Arabic, the present-tense copula is/are/am is usually not expressed.

So Arabic can simply say:

طارد الحشرات وحقيبة الإسعافات الأولية داخل الخيمة

with the sense of:

The insect repellent and the first-aid kit are inside the tent.

If you wanted a past tense, then Arabic would normally use a verb such as كان.

Because طارد الحشرات is an iḍāfa construction (a noun-to-noun construction, often like X of Y).

In an iḍāfa:

• the first noun normally does not take الـ
• the second noun determines whether the whole phrase is definite

So:

• طارد الحشرات = literally repellent of the insects / insect repellent
• because الحشرات is definite, the whole phrase can be understood as definite

The same thing happens in:

• حقيبة الإسعافات الأولية

So even though طارد and حقيبة do not have الـ, the full phrases can still be definite.

It is a noun phrase, specifically an iḍāfa.

Here:

• طارد = repellent / repeller
• الحشرات = the insects

So the structure is basically:

• طارد الحشرات = repellent of insects

It is not adjective + noun, because in Arabic adjectives usually come after the noun they describe and agree with it. Here the relationship is possessive/classifying, not descriptive.

This is also built around an iḍāfa:

• حقيبة = bag / kit
• الإسعافات الأولية = first aid

So the phrase means literally something like:

• the bag of first aid
• more naturally, the first-aid kit

You can think of it as:

1. حقيبة + الإسعافات = an iḍāfa
2. الأولية = an adjective describing الإسعافات

So the internal structure is:

• حقيبةِ [الإسعافاتِ الأوليةِ]

The adjective belongs with الإسعافات, not with حقيبة.

This is a very common Arabic pattern. Non-human plurals often take feminine singular adjective agreement in Modern Standard Arabic.

So although الإسعافات is plural, the adjective appears as:

• الأولية = feminine singular

not as a plural adjective.

This is normal Arabic grammar, and it is especially common in set expressions like:

• الإسعافات الأولية = first aid

داخل here functions as a locative expression meaning inside.

So:

• داخل الخيمة = inside the tent

Arabic often uses داخل directly with the following noun, without needing في.

You can think of it as an adverbial/location phrase. The noun after it, الخيمة, is in a genitive relationship with it.

A fuller alternative such as في داخل الخيمة is possible in some contexts, but داخل الخيمة by itself is perfectly normal and natural.

With full vowel endings, it would commonly be read as:

طارِدُ الحَشَراتِ وَحَقيبَةُ الإِسْعافاتِ الأَوَّلِيَّةِ داخِلَ الخَيْمَةِ

Why?

• طارِدُ — nominative, because it is part of the subject/topic
• الحَشَراتِ — genitive, because it is the second term of an iḍāfa
• حَقيبَةُ — nominative, coordinated with طارد
• الإِسْعافاتِ — genitive, as part of an iḍāfa
• الأَوَّلِيَّةِ — genitive as the adjective of الإسعافات
• داخِلَ — commonly analyzed here as an adverbial accusative of place
• الخَيْمَةِ — genitive after داخل

In normal unvocalized writing, these endings are not shown.

Because the sentence is built as:

• noun phrase + noun phrase + location phrase

The two noun phrases are linked by و (and):

• طارد الحشرات
• حقيبة الإسعافات الأولية

Then the location phrase داخل الخيمة tells where they are.

So the structure is basically:

• [The insect repellent and the first-aid kit] [inside the tent]

That is a very normal nominal-sentence pattern in Arabic.

Yes. Arabic word order is fairly flexible, especially in nominal sentences.

For example, you could also say:

داخل الخيمة طارد الحشرات وحقيبة الإسعافات الأولية

This would still mean essentially the same thing, but it gives the location inside the tent more prominence.

The original version is straightforward and neutral: it introduces the items first, then states their location.

It is a complete sentence in Arabic.

To an English speaker, it may look fragment-like because there is no visible verb such as are. But in Arabic, a present-tense nominal sentence does not need an overt copula.

So this is not broken or incomplete. It is a normal, complete Arabic sentence.