How does one describe a microscope image accurately?? What are several points to be considered in my description??

There are three types of microscopes, optical, electron
and scanning.  I assume you are referring to optical
microscopes.

Optical microscopes include dissecting and
compound types.  Dissecting scopes make use of magnifying lens to examine an intact
specimen (either inorganic or biological), said specimen being lighted by a beam of
direct light as reflected off of the specimen surface.

With
a compound microscope (to which I assume your question applies), a thin slice or section
of the specimen is examined with light transmitted through the specimen from
underneath.  In other words there is a thin slice of tissue (usually on a glass slide)
on the stage of the microscope.  The microscope consists of ocular lenses and objective
lenses above the specimen, condenser lenses beneath the specimen, and a light source
under the condenser.  The specimen slice is usually stained with various dyes to make
microstructure visible.

Your question is somewhat difficult
to answer without knowing more information about what type of specimens you will be
examining.

In general, however, I would say that your
description of the microscopic image should include the structures or shapes or other
details that allow you to identify the specimen and possibly any abnormalities or
diseases that it may have.

So an adequate description of a
flea, as examined microscopically, would include its overall appearance as in insect,
the number of legs present, the bodily divisions, the antennae, and other items that
define it as a flea as opposed to other insects.

Another
different type of specimen such as a human skin biopsy showing common basal cell skin
cancer would be described as skin with a configuration consistent with origin in a
certain body area, in which there is a proliferation of basaloid cells in the epidermis
with pallisading at the base, and invasion into the sub-adjacent dermis.  The dermis
could be described as showing actinic injury (sun damage).  You should then describe the
margins (sides and deep margin) as being free of or involved by
tumor.

In summary, a proper microscopic description gives
details that allow you (and any other expert as well) to identify the specimen and its
abnormalities or disease.  You should be brief and avoid details that have no bearing on
the identification or diagnosis.  And be mindful that a consultant who wishes to provide
a second opinion on your diagnosis will request the slide and examine it herself, rather
than relying solely on your microscopic description.